Tools and gearing and crankshaft assembly for tools

Abstract

A gear drive and crankshaft assembly for a power hand tool includes: an integral gear carrier and crankshaft having opposing first and second ends, wherein the first end includes an offset pin; a gear rotatably coupled to the integral gear carrier and crankshaft via a gear pin; a bearing adapted to receive the integral gear carrier and crankshaft to allow rotation of the integral gear carrier and crankshaft relative to a drive portion; and a gear cover coupled to the drive portion and adapted to limit axial movement of the gear.

Description

Technical Field

[0001] This invention generally relates to power tools. More specifically, this invention relates to a gear drive and crankshaft assembly for a handheld power ratchet tool. Prior Technology

[0002] Power tools driven by electric or pneumatic motors, such as motorized ratchet wrenches, drills, and actuators, are commonly used in automotive, industrial, and household applications to tighten and loosen workpieces (e.g., threaded fasteners) and apply torque and / or angular displacement to them. Power tools (such as cordless powered ratchet wrenches and actuators) typically include an electric motor housed in a casing, along with other components such as switches, controllers, light-emitting diodes (LEDs), and batteries. The casing can be clamshell-type, typically comprising two or more shell sections joined together by fasteners (e.g., screws, rivets, glue, or latches) to cooperatively form the casing.

[0003] Traditional power ratchet tools feature gear drives and crankshaft assemblies to transmit the rotary motion of an electric motor to the ratchet mechanism. However, these tools have a gear carrier, which is typically connected to the crankshaft via a spline or similar coupling. This makes the tool longer to accommodate the connecting components, making it difficult to use in areas with limited space.

[0004] Other conventional power ratchet tools have a one-piece crankshaft and gear carrier. However, these tools utilize ball bearings arranged around the crankshaft to rotate relative to the ratchet housing, which requires enlarging the ratchet housing to accommodate the diameter of the balls used in the ball bearings. Summary of the Invention

[0005] This invention broadly relates to a gear drive and crankshaft assembly for a power ratchet tool. The gear drive and crankshaft assembly includes an integral gear carrier and crankshaft rotatably supported by needle roller bearings in a ratchet housing. The integral gear carrier and crankshaft include a bore adapted to cantilever support a gear operably coupled to a motor output shaft. Because needle roller bearings do not require an inner ring like ball bearings, they have a much smaller outer diameter and a greater static load capacity compared to ball bearings. For example, a needle roller bearing for a 17 mm shaft has a static load rating of 2300 lbs and an outer diameter of 23 mm. A comparable ball bearing for the same 17 mm shaft has a static load capacity of 730 lbs and an outer diameter of 35 mm. Thus, this invention results in a more compact tool that is easier to manufacture and capable of withstanding significantly higher loads compared to current solutions.

[0006] In one embodiment, the invention broadly includes a tool having a drive portion coupled to a housing portion. The tool includes a gear drive and crankshaft assembly arranged in the drive portion. The assembly includes: an integral gear carrier and crankshaft, the integral gear carrier and crankshaft including opposing first and second ends, wherein the first end includes an offset pin; a gear rotatably coupled to the integral gear carrier and crankshaft via a gear pin; a bearing adapted to receive the integral gear carrier and crankshaft to allow rotation of the integral gear carrier and crankshaft relative to the drive portion; and a gear cover coupled to the drive portion and adapted to restrict axial movement of the gear.

[0007] In another embodiment, the invention broadly includes a gear drive and crankshaft assembly for a tool. The assembly includes: an integral gear carrier and crankshaft, the integral gear carrier and crankshaft including opposing first and second ends, wherein the first end includes an offset pin; a gear rotatably coupled to the integral gear carrier and crankshaft via a gear pin; a bearing adapted to receive the integral gear carrier and crankshaft to allow rotation of the integral gear carrier and crankshaft; and a gear cover adapted to restrict axial movement of the gear. Simple Explanation of the Diagram

[0008] For the purpose of facilitating understanding of the subject matter to be protected, embodiments thereof are shown in the accompanying drawings. By observing these drawings and considering them in conjunction with the following description, the subject matter to be protected, its structure, operation, and many advantages should be readily understood and appreciated. Figure 1 is a perspective view of an exemplary powered ratchet hand tool (e.g., a motorized ratchet tool) according to an embodiment of the present invention, which includes a gear drive and a crankshaft assembly. Figure 2 is a plan view of the drive portion of the tool in Figure 1 according to an embodiment of the present invention, wherein the cover has been removed to observe the internal components of the tool. Figure 3 is an exploded perspective view of the gear transmission and crankshaft assembly according to an embodiment of the present invention. Figure 4 is a plan view of the crankshaft of the gear transmission and crankshaft assembly according to an embodiment of the present invention. Figure 5 is another plan view of the crankshaft of the gear transmission and crankshaft assembly according to an embodiment of the present invention. Implementation

[0009] While this disclosure is to be understood as an example of the principles of the invention and is not intended to limit the broad aspects of the invention to any one or more embodiments shown, although the invention may allow for many different forms of embodiments, those illustrated in the drawings and described in detail herein are embodiments of the invention, including preferred embodiments. As used herein, the term "invention" is not intended to limit the scope of the claimed invention, but is merely a term used for illustrative purposes to discuss exemplary embodiments of the invention.

[0010] This invention broadly relates to a gear drive and crankshaft assembly for power-driven tools, such as power ratchet tools. The gear drive and crankshaft assembly includes an integral gear carrier and crankshaft rotatably supported by needle roller bearings in a ratchet housing. The integral gear carrier and crankshaft include a bore adapted to cantilever support a gear operatively coupled to a motor output shaft. Because needle roller bearings do not require an inner ring like ball bearings, they have a much smaller outer diameter and greater static load capacity compared to ball bearings. For example, a needle roller bearing for a 17 mm shaft has a static load rating of 2300 psi and an outer diameter of 23 mm. A comparable ball bearing for the same 17 mm shaft has a static load capacity of 730 psi and an outer diameter of 35 mm. Thus, this invention results in a more compact tool that is easier to manufacture and capable of withstanding significantly higher loads compared to current solutions.

[0011] Referring to Figures 1 through 5, an exemplary powered ratchet tool 100 driven by an electric or pneumatic motor, such as a motorized handheld tool (e.g., a ratchet wrench, drill, and / or driver), includes a housing portion 102 adapted for gripping by a user and a drive portion 104 coupled to the housing portion 102. The drive portion 104 is adapted to apply torque to a workpiece and includes a drive lug 106 adapted to engage a tool (e.g., a socket or head), for example, to drive the workpiece in a known manner. The drive lug 106 is operatively coupled to and driven by a pneumatic or electric motor (not shown) via gear transmission and crankshaft assembly and ratchet mechanism of the drive portion 104, as described below. The drive portion 104 also includes a selection lever 108 adapted to select the desired rotational drive direction (i.e., clockwise or counterclockwise) of the drive lug 106, as described below. For example, the drive portion 104 may be the ratchet head of a ratchet tool.

[0012] The housing portion 102 operatively houses components of the tool 100, such as one or more motors adapted to drive the drive lug 106, a trigger 110 adapted to actuate the motor, a power source (not shown) (e.g., a battery) adapted to power the motor, a controller, and / or a display component 112 (described below). In one embodiment, the housing portion 102 is assembled from two or more clamshell-like housing portions joined together to cooperatively form the housing portion 102 and connect it to the drive portion 104, thereby encapsulating these components within the housing portion 102. The clamshell-like housing portions can be joined together in any known manner, such as screws, rivets, glue, or other fasteners. The housing portion 102 may also include or form a handle for a user to grip during operation of the tool 100.

[0013] The motor can be operatively connected to a power source via trigger 110 in a known manner. The power source can be external (e.g., a wall outlet, generator, external battery, etc.) or internal (e.g., a removable and / or rechargeable battery). Trigger 110 can be adapted to selectively turn the motor on and off, or to allow or stop the flow of power / voltage from the power source to the motor.

[0014] Trigger 110 can be an actuation mechanism employing a button-type actuator or other types of actuators. For example, a user can press trigger 110 inward to selectively draw power from a power source and cause the motor to provide torque to drive portion 104 in the desired direction of rotation. Any suitable trigger 110 or switch can be implemented without departing from the spirit and scope of the invention. For example, trigger 110 can be a toggle actuator, touch-sensitive actuator, slide actuator, or other suitable actuator or device. In another embodiment, trigger 110 can be biased such that pressing trigger 110 inward relative to housing portion 102 operates tool 100, while releasing trigger 110 causes trigger 110 to move outward relative to housing portion 102 to stop operation of tool 100 by the biasing characteristic of trigger 110. Trigger 110 can also be a speed-changing mechanism. In this case, relative actuation or pressing of trigger 110 causes the motor to operate at a different speed as trigger 110 is pressed deeper.

[0015] Display component 112 includes a display 114 adapted to indicate tool information to a user. In one embodiment, display 114 is an LCD. Tool information may include, for example, the tool's status, such as the power level of the power supply, the selected drive direction of the drive lug 106, the power status of the motor, battery charging or status, the output torque of the tool 100, etc. Display component 112 may also include one or more buttons 116 adapted to receive user input, such as user input selecting content that can be displayed on display 114, for selecting tool parameters, such as the drive direction or torque output of the drive lug 106, and / or for further manipulating display 114 to control the tool 100 and / or the parameters of the tool 100.

[0016] A ratchet mechanism is arranged in the drive section 104. The ratchet mechanism includes a connector 118, a first pawl 120 and a second pawl 122, and a ratchet gear 124. When the trigger 110 is actuated, the ratchet mechanism operably connects the drive lug 106 to the motor, thereby driving the lug.

[0017] The connector 118 includes a hole 128 adapted to receive the post 130 for rotatably coupling the connector 118 to the drive portion 104. The post 130 may be integrally formed with the drive portion 104. The connector 118 may also include an opening 132. In one embodiment, the opening 132 is arcuate. The opening 132 is adapted for rotatable coupling to a bushing 134, which is adapted to receive an integral gear carrier and crankshaft 126, as described below.

[0018] The first pawl 120 and the second pawl 122 each include a first pivot hole 136 and a second pivot hole 138, which are adapted to receive pins, rods, shafts, or fasteners, respectively, for pivotally connecting the first pawl 120 and the second pawl 122 to the connector 118. The first pawl 120 includes a first pawl tooth 140 and a first finger 142. The second pawl 122 includes a second pawl tooth 144 and a second finger 146.

[0019] The ratchet gear 124 includes a generally circular body portion 148 having a circumferentially toothed portion 150. A drive lug 106 may be coupled to or integral with the body portion 148. Based on the position of the selector lever 108, the toothed portion 150 selectively engages either a first pawl tooth 140 or a second pawl tooth 144 for selectively engaging one of a first pawl 120 and a second pawl 122 to provide torque drive in either a first rotational drive direction or a second rotational drive direction via the drive lug 106, as described below. The first pawl 120 and the second pawl 122 are each biased toward the ratchet gear by a biasing element 160 (e.g., a spring).

[0020] Selector lever 108 is pivotally connected to cam 158 such that cam 158 rotates together with selector lever 108 to selectively position one of pawls 120, 122 into engagement with ratchet gear 124, thereby selecting the torque drive direction in either a first rotational drive direction or a second rotational drive direction (i.e., clockwise and counterclockwise). For example, to select the first rotational drive direction, as shown in FIG2, cam 158 rotates via selector lever 108 to abut against second finger 146 to overcome the biasing force of bias member 160, thereby disengaging second pawl tooth 144 from the toothed portion 150 of ratchet gear 124. To select the second rotational drive direction, cam 158 rotates via selector lever 108 to abut against first finger 142 to overcome the biasing force of bias member 160, thereby disengaging first pawl tooth 140 from the toothed portion 150 of ratchet gear 124.

[0021] The gear drive and crankshaft assembly 162 is arranged in the drive section 104 and is adapted to operatively connect the motor to the ratchet mechanism to transmit the rotational motion of the motor to the ratchet mechanism. The gear drive and crankshaft assembly 162 includes an integral gear carrier and crankshaft 126, gear pin 164, gear 166, bearing 168, and gear cover 170.

[0022] The integrated gear carrier and crankshaft 126 include opposing first ends 152 and second ends 154. The first end includes an offset pin 156. The offset pin 156 is received by a bushing 134 arranged in an opening 132 of the connector 118. The offset pin 156 is offset from the longitudinal axis of the crankshaft 126 by a distance d0. The second end 154 includes a hole 172 adapted to receive pins 164 respectively to cantilever support gears 166 and rotatably connect gears 166 to the second end 154. In other words, the second end 154 supports only one end of each pin 164. The gear pins 164 have a generally circular cross section and are adapted to be received by gears 166, thereby rotatably connecting gears 166 to the integrated gear carrier and crankshaft 126. Gears 166 serve as planetary gears in a planetary gear transmission system. Although three gears 166 are shown, the invention is not limited thereto, and any suitable number of gears 166 can be used.

[0023] Bearing 168 receives the integrated gear carrier and crankshaft 126 and is adapted to allow the integrated gear carrier and crankshaft 126 to rotate relative to the drive portion 104. In one embodiment, bearing 168 is a needle roller bearing. In one embodiment, the gear drive and crankshaft assembly 162 includes two bearings 168. In another embodiment, the two bearings 168 are respectively arranged at approximately equal distances from their respective opposing first ends 152 and second ends 154, thereby balancing the load forces applied to the integrated gear carrier and crankshaft 126.

[0024] Gear cover 170 is coupled to drive portion 104 and adapted to restrict axial movement of gear 166 relative to drive portion 104. Gear cover 170 includes gear teeth 174 arranged along the inner circumferential surface of gear cover 170, which are adapted to engage gear 166, thereby serving as a ring gear in a planetary gear transmission system. In one embodiment, gear cover 170 includes radial protrusions 176 adapted to engage the internal geometry of drive portion 104 to restrict rotational movement of gear cover 170 relative to drive portion 104. Although four protrusions 176 are shown, the invention is not limited thereto, and any number of protrusions 176 may be used.

[0025] During operation, when trigger 110 is actuated, the motor drives the integrated gear carrier and crankshaft 126 to rotate about the longitudinal axis of the integrated gear carrier and crankshaft 126 via gear 166, thereby driving the connecting member 118 to move back and forth about column 130, thereby moving the pawls 120 and 122 accordingly. Thus, one of the first pawls 120 and the second pawl 122, which selectively engages with the ratchet gear 124, will drive the drive lug 106 in the selected direction of rotation (e.g., clockwise or counterclockwise).

[0026] As described above, various aspects of the invention have been described in relation to a powered ratchet tool, as illustrated in the figures. However, it should be understood that aspects of the invention can be implemented in other hand tools. For example, but not limited to, the hand tool can be a ratchet wrench, impact wrench, open-end wrench, screwdriver, nut wrench, drill, or any other tool capable of applying torque to a workpiece.

[0027] As used herein, the term "connection" can mean any direct or indirect physical, electrical, magnetic, or other connection between two objects. The term "connection" is not limited to a fixed, direct connection between two objects.

[0028] The content set forth in the foregoing description and figures is provided by way of illustration only and is not intended to be limiting. Although specific embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications can be made without departing from the broader aspects of the inventors' contributions. The actual scope of protection sought is intended to be limited to the following claims when viewed from a suitable perspective based on the prior art.

[0029] 100: Power ratchet tool 102: Shell portion 104 driver section 106: Drive lug 108: Selection bar 110: Trigger 112: Display Component 114: Monitor 116: Button 118: Connector 120: First pawl 122: Second pawl 124: Ratchet gear 126: Crankshaft 128: Kong 130: column 132: Opening 134: Bushing 136: First pivot hole 138: Second pivot hole 140: First ratchet tooth 142: First finger section 146: Second finger 144: Second ratchet tooth 148: Main Body 150: Toothed part 152: First End 154: Second End 156: Offset pin 158: Cam 160: Offset component 162: Gear drives and crankshaft assemblies 164: Gear pin 166: Gear 168: Bearing 170: Gear cover 172: Kong 174: Gear teeth 176: Radial protrusion d0: Offset distance

Claims

1. A tool having a drive portion coupled to a housing portion and a motor disposed within the housing portion, the motor including a motor output shaft, the tool comprising: A gear drive and crankshaft assembly disposed in the drive portion, the gear drive and crankshaft assembly comprising: an integral gear carrier and crankshaft, the integral gear carrier and crankshaft including opposing first and second ends, wherein the first end includes an offset pin; a gear rotatably coupled to the integral gear carrier and crankshaft via a gear pin; a bearing adapted to receive the integral gear carrier and crankshaft to allow rotation of the integral gear carrier and crankshaft relative to the drive portion; and an integral gear cover coupled to the drive portion and including a first cover end having an opening adapted to receive the gear, an annular gear adapted to engage the gear, and a second cover end having a wall surface extending radially inward and adapted to restrict axial movement of the gear, wherein the wall surface includes a hole adapted to receive the motor output shaft.

2. The tool as claimed in claim 1 further includes a ratchet mechanism, the ratchet mechanism comprising: A connecting element that is rotatably connected to the integrated gear carrier and crankshaft; A ratchet gear having a toothed portion and adapted to be selectively driven in either a first drive direction or a second drive direction; a first pawl and a second pawl, the first pawl and the second pawl being pivotally connected to the connector and adapted to selectively engage the toothed portion to select one of the first drive direction and the second drive direction, wherein the first drive direction is selected when the first pawl engages with the toothed portion and the second pawl disengages from the toothed portion, and the second drive direction is selected when the first pawl disengages from the toothed portion and the second pawl engages with the toothed portion.

3. The tool as claimed in claim 1, wherein the second end of the integrated gear carrier and crankshaft includes a hole adapted to receive the gear pin to cantilever support the gear and rotatably connect the gear to the second end.

4. The tool as claimed in claim 1, wherein the gear drive and crankshaft assembly includes three gears rotatably coupled to an integral gear carrier.

5. The tool as claimed in claim 1, wherein the bearing is a needle roller bearing.

6. The tool as claimed in claim 1, wherein the gear drive and crankshaft assembly includes two bearings.

7. The tool as claimed in claim 1, wherein the ring gear includes gear teeth arranged along the inner circumferential surface of the integral gear cover, and the gear teeth are adapted to engage the gear.

8. The tool as claimed in claim 1, wherein the integral gear cover includes radial protrusions adapted to engage the internal geometry of the drive portion.

9. The tool as claimed in claim 8, wherein the integral gear cover includes the four protrusions.

10. A gear drive and crankshaft assembly for a tool, the tool having a motor with a motor output shaft, the gear drive and crankshaft assembly comprising: An integral gear carrier and crankshaft, the integral gear carrier and crankshaft including opposing first and second ends, wherein the first end includes an offset pin; a gear rotatably coupled to the integral gear carrier and crankshaft by a gear pin; a bearing adapted to receive the integral gear carrier and crankshaft to allow rotation of the integral gear carrier and crankshaft; and an integral gear cover including a first cover end having an opening adapted to receive the gear, an annular gear adapted to engage the gear, and a second cover end having a wall surface extending radially inward and adapted to restrict axial movement of the gear, wherein the wall surface includes a hole adapted to receive the motor output shaft.

11. The gear drive and crankshaft assembly as claimed in claim 10, wherein the second end of the integral gear carrier and crankshaft includes a bore adapted to receive the gear pins to cantilever support the gears and rotatably connect the gears to the second end.

12. The gear drive and crankshaft assembly as claimed in claim 10, wherein the gear drive and crankshaft assembly includes three gears rotatably coupled to an integral gear carrier.

13. The gear drive and crankshaft assembly as claimed in claim 10, wherein the bearing is a needle roller bearing.

14. The gear drive and crankshaft assembly as claimed in claim 10, wherein the gear drive and crankshaft assembly includes two bearings.

15. The gear drive and crankshaft assembly as claimed in claim 10, wherein the ring gear includes gear teeth arranged along the inner circumferential surface of the integral gear cover, and the gear teeth are adapted to engage the gear.

16. The gear drive and crankshaft assembly as claimed in claim 10, wherein the integral gear cover includes radial protrusions adapted to engage the internal geometry of the drive portion of the tool.

17. The gear drive and crankshaft assembly as claimed in claim 16, wherein the integral gear cover includes the four protrusions.

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