Labor-saving crank structure and assembly of bicycle

Abstract

The invention discloses a labor-saving crank structure of a bicycle, comprising a crank mechanism, a transmission mechanism and a swing arm assembly, wherein the crank mechanism comprises a crank, a shaft end gear and a pedal end gear arranged on the crank; the transmission mechanism is arranged inside the crank, and comprises a rotating shaft and a first gear and a second gear connected to the rotating shaft, the first gear meshes with the shaft end gear for transmission, and the second gear meshes with the pedal end gear for transmission; the swing arm assembly comprises a first swing arm and a second swing arm, and the two ends of the second swing arm are respectively connected to the first swing arm and the pedal end gear. Thus, not only is the structure simple, but also stable transmission can be performed in a circular motion mode.

Description

Technical Field

[0001] The invention relates to the technical field of bicycle crank structures, and in particular to a labor-saving crank structure and assembly of a bicycle. Background Art

[0002] For the sake of health or to reduce the emission of harmful gases and carbon, most people will make good use of part of their time to do sports such as jogging, walking or cycling. Among them, cycling can best relax the rider's body, mind and spirit because of its short- and medium-distance travel effects. With a large number of bicycle lanes in various counties and cities, cycling has obviously become one of the most popular activities for the whole people.

[0003] The crank of a bicycle is a rod of fixed length, which is used to connect the pedals to the central axis of the bicycle. When the bicycle is in operation, the user steps on the pedals, causing the pedals to rotate around the central axis in a circular motion with the crank length as the radius, and drives the bicycle's driving device such as the sprocket, chain and other components to move the bicycle forward.

[0004] The existing crank devices widely used in bicycles cannot extend the crank to increase the length of the lever arm when the pedals rotate to the required force application point, so the effect of increasing the torque cannot be achieved. Some designs may use the retractable crank feature, but the design of such retractable cranks is not ergonomic and cannot make a circular motion regularly and by inertia. It is essentially a laborious design, which is not only complex in structure but also easy to cause fatigue to the user.

[0005] In view of this, the inventor has focused on the above-mentioned deficiencies of the prior art, conducted intensive research and applied theoretical knowledge to try his best to solve the above-mentioned problems, which has become the goal of the improvement of the present invention. Summary of the invention

[0006] The purpose of the present invention is to provide a labor-saving crank structure and assembly for a bicycle, which achieves a labor-saving effect through a force-applying arm composed of a swing arm assembly and a crank, and has not only a simple structure but also can perform stable transmission in a circular motion.

[0007] In order to achieve the above-mentioned purpose, the present invention provides a labor-saving crank structure for a bicycle, comprising a crank mechanism, a transmission mechanism and a swing arm assembly, wherein the crank mechanism comprises a crank, a shaft-end gear arranged at one end of the crank and a pedal-end gear arranged at the other end of the crank; the transmission mechanism is arranged inside the crank, and the transmission mechanism comprises a rotating shaft and a first gear and a second gear connected to the two ends of the rotating shaft, the first gear meshes with the shaft-end gear for transmission, and the second gear meshes with the pedal-end gear for transmission; the swing arm assembly comprises a first swing arm and a second swing arm, and the two ends of the second swing arm are respectively connected to one end of the first swing arm and the pedal-end gear.

[0008] Preferably: wherein the crank includes an outer shell and an inner shell corresponding to the outer shell, the outer shell is provided with a first connecting hole, the inner shell extends with a shaft sleeve, and a front convex column and a rear convex column are respectively extended at both ends of the pedal end gear, the front convex column corresponds to the first connecting hole and is passed through, and the rear convex column is jointly accommodated in the shaft sleeve through a bearing, so that the pedal end gear is supported between the outer shell and the inner shell.

[0009] Preferably, a cylindrical column is extended from the outer shell, a second connecting hole is provided in the inner shell, and the shaft end gear passes through the second connecting hole and is sleeved on the cylindrical column.

[0010] Preferably, the front boss is provided with a positioning plane, the second swing arm is provided with an embedding groove and a fixing plane formed in the embedding groove, the front boss is inserted into the embedding groove, and the fixing plane and the positioning plane are locked with each other.

[0011] Preferably, the end surface of the front convex column is provided with two positioning holes, the second swing arm is provided with two through holes connected to the embedding groove, and the two positioning holes are configured corresponding to the two through holes to allow a screw-fixing element to pass through and lock.

[0012] Preferably: wherein the transmission mechanism also includes a connecting sleeve, the rotating shaft includes a first rotating shaft and a second rotating shaft, the first gear is connected to one end of the first rotating shaft, the second gear is connected to one end of the second rotating shaft, and the connecting sleeve is sleeved on the other ends of the first rotating shaft and the second rotating shaft and rotates with the first rotating shaft and the second rotating shaft.

[0013] Preferably: wherein the crank includes an outer shell and an inner shell corresponding to the outer shell, the transmission mechanism also includes at least two fixed sleeves and at least two positioning sleeves, the fixed sleeves are sleeved on the first rotating shaft and the second rotating shaft at intervals and are clamped between the inner shell and the outer shell, the positioning sleeves are sleeved on the first rotating shaft and the second rotating shaft at intervals and are between any two adjacent fixed sleeves.

[0014] In order to achieve the above-mentioned other purpose, the present invention provides a labor-saving crank assembly for a bicycle, the bicycle has a middle bearing seat, the labor-saving crank assembly includes a middle shaft, a group of labor-saving crank structures and a group of stop members, the middle shaft passes through the middle bearing seat; each of the labor-saving crank structures is connected to one end of the middle shaft; each of the stop members is sleeved on each of the shaft end gears and is located between each of the cranks and the middle bearing seat.

[0015] Preferably, it further comprises a sprocket, wherein the sprocket is sleeved on the shaft end gear and is located between one of the cranks and one of the stop members.

[0016] Preferably: the bicycle also has a left fork tube and a right fork tube connected to the middle bearing seat, each of the stopping components includes a ring body, an arm body extending from the ring body and a stop rod connected to one end of the arm body away from the ring body, one of the stop rods abuts against the lower edge of the left fork tube, and the other stop rod abuts against the upper edge of the right fork tube.

[0017] In summary, the beneficial technical effects of the present invention are:

[0018] The present invention has the following effects: when the pedal is stepped on to make the crank do circular motion, there is no problem of upper and lower dead points and transmission problems such as setbacks. With the help of the transmission of the bevel helical teeth and the bevel gear, close contact can be achieved regardless of whether the crank is rotating in the forward or reverse direction, thereby reducing the generation of noise and improving the transmission efficiency and positioning accuracy. The first swing arm and the second swing arm are designed in an arc shape, which can prevent the front wheel from contacting the swing arm assembly during the turning process. By utilizing the penetration combination of each sleeve groove and each plug block, it is effectively prevented that each swing arm will be bent, deformed or pulled apart due to long-term operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The figure is an exploded view of the labor-saving crank structure of the bicycle of the present invention.

[0020] Figure 2 It is a combined sectional view of the labor-saving crank structure of the bicycle of the present invention.

[0021] Figure 3It is an exploded view of the swing arm assembly of the present invention.

[0022] Figure 4 This is an exploded view of the overall components of the labor-saving crank of the present invention.

[0023] Figure 5 This is a combined diagram of the labor-saving crank assembly of the present invention.

[0024] Figure 6 This is a combined sectional view of the labor-saving crank assembly of the present invention.

[0025] Figure 7 This is a diagram of the combination of the labor-saving crank assembly, pedals and a frame of the present invention.

[0026] Figure 8 This is a combined diagram of the labor-saving crank assembly of the present invention applied to a bicycle.

[0027] Fig. 9 This is a diagram showing the use status of the labor-saving crank assembly of the present invention.

[0028] In the figure,

[0029] 1: Labor-saving crank structure

[0030] 10: Crank mechanism

[0031] 11: Crank

[0032] 111: Outer shell

[0033] 112: Cylindrical column

[0034] 113: First connection hole

[0035] 114: screw hole

[0036] 115: Rectangular tapered hole

[0037] 116: Inner shell

[0038] 117: Second connection hole

[0039] 118: Bushing

[0040] 119:Piercing

[0041] A: Container

[0042] B: Raised strip

[0043] C: Screw-on element

[0044] 12: shaft end gear

[0045] 121: Umbrella-shaped helical teeth

[0046] 122: Embedded Strip

[0047] 13: Pedal end gear

[0048] 131: Anterior convex column

[0049] 132: Rear convex column

[0050] 133: Umbrella-shaped helical teeth

[0051] 134: Positioning plane

[0052] 135: Positioning hole

[0053] 14: Bearing

[0054] 20: Transmission mechanism

[0055] 21: Rotating shaft

[0056] 211: First axis

[0057] 212: Second axis

[0058] 22: First gear

[0059] 23: Second gear

[0060] 24: Connecting sleeve

[0061] 25:Fixed sleeve

[0062] 26: Positioning sleeve

[0063] 30: Swing arm assembly

[0064] 31: First spiral arm

[0065] 311: pedal support column

[0066] 312: Insert block

[0067] 313: socket slot

[0068] 32: Second spiral arm

[0069] 321:Through hole

[0070] 322: receiving slot

[0071] 323: Embed Block

[0072] 324: Bezel

[0073] 325: Fixed plane

[0074] 326:Piercing

[0075] 4: Middle axis

[0076] 41: Spindle section

[0077] 42: Extension

[0078] 421: Rectangular cone

[0079] 422: screw hole

[0080] 43: Bolt

[0081] 5: Stop member

[0082] 51: Ring

[0083] 511: Embed

[0084] 512: groove

[0085] 52: Arm

[0086] 53: Resist the bar

[0087] 6: Sprocket

[0088] 8. Bicycle

[0089] 81: Frame

[0090] 82: Middle bearing seat

[0091] 83: Left fork tube

[0092] 84:Right fork tube

[0093] 85: Foot pedal

[0094] 86:Embedded ring DETAILED DESCRIPTION

[0095] The present invention is further described in detail below with reference to the accompanying drawings.

[0096] See also Figures 1 to 3 As shown, the present invention provides a labor-saving crank structure for a bicycle, which mainly includes a crank mechanism 10, a transmission mechanism 20 and a swing arm assembly 30.

[0097] The crank mechanism 10 mainly includes a crank 11, a shaft end gear 12 and a pedal end gear 13. The crank 11 of this embodiment mainly includes an outer shell 111 and an inner shell 116. A cylindrical column 112 extends from one end of the outer shell 111, and a first connecting hole 113 is provided at the other end. A receiving groove A is opened inside the outer shell 111 between the cylindrical column 112 and the first connecting hole 113; in addition, at least two screw holes 114 are evenly distributed on the periphery of the inner side surface of the outer shell 111; furthermore, a rectangular tapered hole 115 is formed inside the cylindrical column 112.

[0098] The shape of the inner shell 116 corresponds to the shape of the outer shell 111. A second connecting hole 117 is provided at one end of the inner shell 116, and a shaft sleeve 118 is provided at the other end of the inner shell 116, which is configured corresponding to the aforementioned first connecting hole 113, and a convex strip B extends inside the inner shell 116 between the second connecting hole 117 and the shaft sleeve 118. This convex strip B is embedded and fixed corresponding to the aforementioned receiving groove A; in addition, at least two evenly distributed through holes 119 are provided on the periphery of the inner shell 116, and each through hole 119 is respectively configured corresponding to the aforementioned screw hole 114, so as to allow a screw or other screw-fixing element C to pass through and lock.

[0099] The shaft end gear 12 is a static gear (i.e. fixed and does not rotate), which is sleeved on the cylindrical column 112 and then passed through the second connecting hole 117, so that the shaft end gear 12 is supported between the cylindrical column 112 and the inner shell 116. At least two annularly arranged umbrella-shaped bevel teeth 121 are formed on one side of the shaft end gear 12, and at least two embedded strips 122 are provided at one end of the shaft end gear 12 away from each umbrella-shaped bevel teeth 121.

[0100] The pedal end gear 13 is a moving gear (i.e., it is driven by the transmission mechanism 20 to rotate during the rotation of the crank 11), and a front boss 131 and a rear boss 132 are respectively extended from its front and rear ends. The front boss 131 is connected to the first connecting hole 113, and the rear boss 132 is accommodated in the aforementioned sleeve 118 through a bearing 14, so that the pedal end gear 13 is supported between the outer shell 111 and the inner shell 116. At least two umbrella-shaped bevel teeth 133 arranged in a ring are formed on one side of the pedal end gear 13; a positioning plane 134 is provided on the front boss 131 of the pedal end gear 13; and two positioning holes 135 are provided on the end face of the front boss 131.

[0101] The transmission mechanism 20 is disposed inside the crank 11, and mainly includes a rotating shaft 21, a first gear 22 and a second gear 23. The first gear 22 and the second gear 23 are respectively connected to the two ends of the rotating shaft 21, and the first gear 22 and the second gear 23 are both bevel gears, wherein the first gear 22 is meshed with the aforementioned shaft end gear 12 for transmission, and the second gear 23 is meshed with the aforementioned pedal end gear 13 for transmission. The gear ratio of the first gear 22 to the shaft end gear 12 is 1:3, and the gear ratio of the second gear 23 to the pedal end gear 13 is also 1:3, so that an excellent transmission effect can be achieved; and the number of teeth of the pedal end gear 13 can be equal to or less than the number of teeth of the shaft end gear 12 for configuration.

[0102] Furthermore, the transmission mechanism 20 further includes a connecting sleeve 24, at least two fixed sleeves 25 and at least two positioning sleeves 26. The rotating shaft 21 of this embodiment includes a first rotating shaft 211 and a second rotating shaft 212. The first gear 22 is connected to one end of the first rotating shaft 211, and the second gear 23 is connected to one end of the second rotating shaft 212. The connecting sleeve 24 is sleeved on the other ends of the first rotating shaft 211 and the second rotating shaft 212, and the connecting sleeve 24 rotates with the first rotating shaft 211 and the second rotating shaft 212. At least two fixed sleeves 25 are sleeved on the first rotating shaft 211 and the second rotating shaft 212 at intervals, and are clamped between the convex strip B of the inner shell 116 and the groove A of the outer shell 111; at least two positioning sleeves 26 are sleeved on the first rotating shaft 211 and the second rotating shaft 212 at intervals, and are between any two adjacent fixed sleeves 25.

[0103] The swing arm assembly 30 includes a first swing arm 31 and a second swing arm 32. Both the first swing arm 31 and the second swing arm 32 are arc-shaped swing arms. The first swing arm 31 is formed between the crank 11 and the second swing arm 32, and is provided with a pedal receiving column 311, and a sleeve groove 313 and an insert block 312 are provided at one end away from the pedal receiving column 311. The second swing arm 32 is provided with a through hole 321, and an insert block 323 and a receiving groove 322 are provided at one end away from the through hole 321; wherein the pedal receiving column 311 is provided with the aforementioned through hole 321, and the insert groove 322 and the insert block 323 are respectively combined with the insert block 312 and the sleeve groove 313 of the first swing arm 31.

[0104] Furthermore, an embedding groove 324 and a locking plane 325 formed in the embedding groove 324 are provided on the inner side of the second swing arm 32 at the side of the through hole 321, and two through holes 326 connected to the embedding groove 324 are opened on the second swing arm 32; wherein the embedding groove 324 is for the aforementioned front boss 131 to be inserted into, the locking plane 325 of the second swing arm 32 is engaged with the positioning plane 134 of the front boss 131, and each positioning hole 135 of the front boss 131 is configured corresponding to each through hole 326, so as to allow a screw or other screw-fixing element to pass through and lock.

[0105] See also Figures 4 to 7 As shown, the present invention also provides a labor-saving crank assembly, which mainly includes a middle shaft 4, a group of labor-saving crank structures 1 and a group of stop members 5.

[0106] The central axis 4 mainly includes a main shaft section 41 and an extension section 42 protruding outward from the two ends of the main shaft section 41. A rectangular tapered column 421 is provided on the extension section 42 for the aforementioned cylindrical column 112 to be sleeved and combined with its rectangular tapered hole 115. A screw hole 422 is also provided on the end surface of the extension section 42 for a bolt 43 to pass through and lock it.

[0107] Each stop member 5 mainly includes a ring body 51, an arm body 52 extending from the ring body 51 and a stop rod 53 connected to one end of the arm body 52 away from the ring body 51. At least two embedded blocks 511 are provided on the outer periphery of the ring body 51, and at least two embedded grooves 512 are provided on the inner peripheral wall of the ring body 51. The embedded grooves 512 are for the embedding strips 122 of the aforementioned shaft end gear 12 to be embedded and combined.

[0108] Furthermore, the labor-saving crank assembly of the present invention further includes a sprocket 6 , which is sleeved on the cylindrical column 112 of the shaft end gear 12 and is located between one of the cranks 11 and one of the stop members 5 .

[0109] See also Figure 8 and Fig. 9 As shown, the labor-saving crank assembly of the present invention is applied to a bicycle 8, which has a frame 81, a middle bearing seat 82 is installed at the lower part of the frame 81, and a left fork tube 83 and a right fork tube 84 formed on the right side of the left fork tube 83 extend from the middle bearing seat 82 toward the rear wheel. In addition, the bicycle 8 also includes a set of pedals 85, a set of embedded rings 86 and other necessary devices.

[0110] During assembly, the middle shaft 4 is inserted into the middle bearing seat 82, and each embedded ring 86 is locked in the middle bearing seat 82 to restrict the middle shaft 4 in the middle bearing seat 82, wherein the middle shaft 4 can rotate in the middle bearing seat 82; the stopper member 5 is then embedded and positioned corresponding to each embedded ring 86, so that the stopper member 5 is formed on both sides of the middle bearing seat 82, and the stopper rod 53 of the stopper member 5 on the left side is pressed against the lower edge of the left fork tube 83, and the stopper rod 53 on the right side is pressed against the lower edge of the left fork tube 83. The abutment rod 53 of the component 5 is pressed against the upper edge of the right fork tube 84; then, the rectangular tapered hole 115 of the cylindrical column 112 is aligned with the rectangular tapered column 421 of the middle shaft 4 for sleeve connection, and at the same time, the insert strips 122 of the shaft end gear 12 are embedded and combined with the insert grooves 512 of the ring body 51; finally, a bolt 43 is inserted into the cylindrical column 112 of the crank 11 and locked with the screw hole 422 of the middle shaft 4, so that the rotation of the crank 11 can drive the middle shaft 4 to rotate.

[0111] To further explain, since the force arm from the axis of the shaft end gear 12 to the connection between the first swing arm 31 and the second swing arm 32 is greater than the length of the crank 11, according to the torque principle (M=F*d, F: force, d: force arm), under the condition of the same torque, increasing the length of the force arm will reduce the applied force.

[0112] During operation, a force is applied to the pedal 85, and the crank mechanism 10 drives the middle shaft 4 and the sprocket 6 to rotate along with the crank 11 through the cylindrical column 112. When the swing arm assembly 30 rotates downward from the vertex position, the first gear 22 is driven by the shaft end gear 12, thereby driving the rotating shaft 21 and the second gear 23 to rotate, and the second gear 23 drives the pedal end gear 13 to rotate, so that the swing arm assembly 30 maintains a constant angle with the ground, and the motion trajectory of the center point of the pedal 85 forms a nearly circular motion. In addition, the motion direction of the swing arm assembly 30 is opposite to the motion direction of the crank 11.

[0113] The embodiments of this specific implementation method are all preferred embodiments of the invention, and are not intended to limit the protection scope of the invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the invention should be included in the protection scope of the invention.

Claims

1. A labor-saving crank structure for a bicycle, characterized in that: include: A crank mechanism, comprising a crank, a shaft end gear disposed at one end of the crank and a pedal end gear disposed at the other end of the crank; a transmission mechanism, arranged inside the crank, the transmission mechanism comprising a rotating shaft and a first gear and a second gear connected to both ends of the rotating shaft, the first gear meshing with the shaft end gear for transmission, and the second gear meshing with the pedal end gear for transmission; and A swing arm assembly, comprising a first swing arm and a second swing arm, wherein two ends of the second swing arm are respectively connected to one end of the first swing arm and the pedal end gear; The transmission mechanism further includes a connecting sleeve, the rotating shaft includes a first rotating shaft and a second rotating shaft, the first gear is connected to one end of the first rotating shaft, the second gear is connected to one end of the second rotating shaft, and the connecting sleeve is sleeved on the other ends of the first rotating shaft and the second rotating shaft and rotates with the first rotating shaft and the second rotating shaft.

2. The labor-saving crank structure for a bicycle as claimed in claim 1, characterized in that: The crank comprises an outer shell and an inner shell corresponding to the outer shell, the outer shell is provided with a first connecting hole, the inner shell extends with a shaft sleeve, and a front convex column and a rear convex column are respectively extended from both ends of the pedal end gear, the front convex column corresponds to the first connecting hole and is passed through, and the rear convex column is accommodated in the shaft sleeve through a bearing, so that the pedal end gear is supported between the outer shell and the inner shell.

3. The labor-saving crank structure for a bicycle as claimed in claim 2, characterized in that: A cylindrical column is extended from the outer shell, a second connecting hole is provided in the inner shell, and the shaft end gear passes through the second connecting hole and is sleeved on the cylindrical column.

4. The labor-saving crank structure for a bicycle as claimed in claim 3, characterized in that: The front boss is provided with a positioning plane, the second swing arm is provided with an embedding groove and a clamping plane formed in the embedding groove, the front boss is inserted into the embedding groove, and the clamping plane and the positioning plane are locked with each other.

5. The labor-saving crank structure for a bicycle as claimed in claim 4, characterized in that: The end surface of the front convex column is provided with two positioning holes, and the second swing arm is provided with two through holes connected to the embedding groove, and the two positioning holes are configured corresponding to the two through holes to allow a screw-fixing element to pass through and lock.

6. The labor-saving crank structure for a bicycle according to claim 1, characterized in that: The crank includes an outer shell and an inner shell corresponding to the outer shell, and the transmission mechanism also includes at least two fixed sleeves and at least two positioning sleeves. The fixed sleeves are sleeved on the first rotating shaft and the second rotating shaft at intervals and are clamped between the inner shell and the outer shell. The positioning sleeves are sleeved on the first rotating shaft and the second rotating shaft at intervals and are located between any two adjacent fixed sleeves.

7. A labor-saving crank assembly for a bicycle, characterized in that: The bicycle has a middle bearing seat, and the labor-saving crank assembly includes: A middle shaft, passing through the middle bearing seat; A group of labor-saving crank structures according to any one of claims 1 to 6, each of which is connected to one end of the middle shaft; and A group of stop components, each of which is sleeved on each of the shaft end gears and is located between each of the cranks and the middle bearing seat.

8. The labor-saving crank assembly for a bicycle as claimed in claim 7, characterized in that: It also includes a sprocket, which is sleeved on the shaft end gear and is located between one of the cranks and one of the stop members.

9. The labor-saving crank assembly for a bicycle as claimed in claim 7, characterized in that: The bicycle also has a left fork tube and a right fork tube connected to the middle bearing seat, and each of the stop components includes a ring body, an arm body extending from the ring body, and a stop rod connected to one end of the arm body away from the ring body, wherein the stop rod abuts against the lower edge of the left fork tube, and the other stop rod abuts against the upper edge of the right fork tube.

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