Pawl mechanism for ratchet tools

Abstract

This invention broadly relates to pawl mechanisms for tools such as ratchet wrenches. The pawl mechanism includes a first pawl and a second pawl, which selectively engage with a drive gear to provide a first rotational drive direction and a second rotational drive direction. Each of the first and second pawls includes an outwardly projecting hook-shaped protrusion that engages a corresponding recess or groove in a pawl carrier to operably connect a pawl carrier to the first and second pawls. The pawl carrier includes a first pawl cavity and a second pawl cavity that receive the corresponding first and second pawls. The pawl carrier also includes a first recess or groove and a second recess or groove adjacent to the corresponding first and second pawl cavities, and the first recess or groove and the second recess or groove accommodate the hook-shaped protrusion.

Description

Technical Field

[0001] This application generally relates to pawl mechanisms, and more specifically to pawl mechanisms for ratchet tools. Background Technology

[0002] Many double-pawl mechanisms are known and used. Typically, these mechanisms are incorporated into tools (e.g., ratchet wrenches) that have a drive portion that engages, for example, a socket or fastener head. These tools generally allow selection of a first drive direction and a second drive direction. For example, a first drive direction can be selected for a double-pawl mechanism, thus providing torque when the tool engages with the fastener head and rotates in the first direction, while providing slippage or engagement when rotating in the second direction. A second drive direction opposite to the first drive direction can be selected for the double-pawl mechanism, providing torque and slippage in the opposite direction.

[0003] When operating a steerable double pawl mechanism, there is usually a manually actuated part, generally called a reversing lever, which engages one pawl with the drive gear and disengages the other pawl from the drive gear. The driving direction of the drive unit depends on which of the two pawls is engaged with the drive gear. Summary of the Invention

[0004] This invention broadly relates to pawl mechanisms for tools such as ratchet wrenches. The pawl mechanism includes a first pawl and a second pawl, which selectively engage with a drive gear to provide a first rotational drive direction and a second rotational drive direction. Each of the first and second pawls includes an outwardly projecting hook-shaped protrusion that engages a corresponding recess or groove in a pawl carrier to operably connect a pawl carrier to the first and second pawls. The pawl carrier includes a first pawl pocket and a second pawl pocket that receive the corresponding first and second pawls. The pawl carrier also includes a first recess or groove and a second recess or groove adjacent to the corresponding first and second pawl pockets, and the first recess or groove and the second recess or groove accommodate the hook-shaped protrusion.

[0005] When the pawl carrier rotates (via the rotation of the reversing lever) to select the first rotational drive direction, the pawl carrier causes the first pawl to move into engagement with the drive gear and pulls the second pawl away from or out of engagement with the drive gear. Similarly, when the pawl carrier rotates (via the rotation of the reversing lever) to select the second rotational drive direction, the pawl carrier causes the second pawl to move into engagement with the drive gear and pulls the first pawl away from or out of engagement with the drive gear.

[0006] In one embodiment, the present invention relates to a pawl mechanism for a ratchet tool, wherein the ratchet tool includes a drive gear having gear teeth. The pawl mechanism includes: a pawl carrier including a first pawl cavity and a first groove; and a first pawl disposed in the first pawl cavity. The first pawl includes a first pawl tooth selectively engaging with the gear teeth to select a first rotational drive direction, a first protrusion extending away from the first pawl tooth, and a first projection extending from the first protrusion and into the first groove.

[0007] In another embodiment, the present invention relates to a ratchet tool. The ratchet tool includes: a ratchet head having a drive cavity and a pawl cavity; a drive gear having gear teeth and disposed in the drive cavity; and a pawl carrier disposed in the pawl cavity and including a first pawl recess and a second pawl recess facing the drive gear, as well as a first groove and a second groove. A reversing lever is coupled to the pawl carrier and is movable to select either a first rotational drive direction or a second rotational drive direction. The first pawl is disposed in the pawl cavity and in the first pawl recess, the first pawl including first pawl teeth that selectively engage with gear teeth when the first rotational drive direction is selected. The first pawl includes a first protrusion extending away from the first pawl teeth, and a first projection extending from the first protrusion and into the first groove. The second pawl is disposed in the pawl cavity and in the second pawl recess, the second pawl including second pawl teeth that selectively engage with gear teeth when the second rotational drive direction is selected. The second pawl also includes a second protrusion extending away from the second pawl teeth, and a second projection extending from the second protrusion into the second groove. Attached Figure Description

[0008] To facilitate understanding of the subject matter for which protection is sought, embodiments thereof are shown in the accompanying drawings. When considered in conjunction with the following description, the subject matter for which protection is sought, its construction and operation, and its many advantages should be readily understood and appreciated from an examination of its embodiments.

[0009] Figure 1 This is an exploded view of a ratchet tool according to an embodiment of the present invention.

[0010] Figure 2 This is a side view of the head of the ratchet tool with the cover plate removed. Detailed Implementation

[0011] While the invention is permissible in many different forms, preferred embodiments of the invention, which will be described in detail herein, are shown in the accompanying drawings. It should be understood that this disclosure is intended to be an example of the principles of the invention and not to limit the broad aspects of the invention to the embodiments shown. 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.

[0012] This invention broadly relates to pawl mechanisms for tools such as ratchet wrenches. The pawl mechanism includes a first pawl and a second pawl, which selectively engage with a drive gear to provide a first rotational drive direction and a second rotational drive direction. Each of the first and second pawls includes an outwardly projecting hook-shaped protrusion that engages a corresponding recess or groove in a pawl carrier to operably connect a pawl carrier to the first and second pawls. The pawl carrier includes a first pawl cavity and a second pawl cavity that receive the corresponding first and second pawls. The pawl carrier also includes a first recess or groove and a second recess or groove adjacent to the corresponding first and second pawl cavities, and the first recess or groove and the second recess or groove accommodate the hook-shaped protrusion.

[0013] When the pawl carrier rotates (via the rotation of the reversing lever) to select the first rotational drive direction, the pawl carrier causes the first pawl to move into engagement with the drive gear and pulls the second pawl away from or out of engagement with the drive gear. Similarly, when the pawl carrier rotates (via the rotation of the reversing lever) to select the second rotational drive direction, the pawl carrier causes the second pawl to move into engagement with the drive gear and pulls the first pawl away from or out of engagement with the drive gear.

[0014] refer to Figure 1 and Figure 2 The tool 100, such as a ratchet wrench, includes a head 102 and a handle 104 extending from the head 102. The head 102 includes a cavity 106 adapted to receive internal and external components of the tool 100 for providing torque to a workpiece (not shown, such as a socket) or other tools or fasteners. The internal and / or external components may respectively include a drive gear 112, a pawl carrier 114, a first pawl 116 and a second pawl 118, and a reversing lever 120, etc.

[0015] Cavity 106 may include several portions for receiving and holding components, such as a first cavity 108 and a second cavity 110 that overlap or communicate with each other. The first cavity 108 (also referred to as drive cavity 108) is adapted to receive drive gear 112, and the second cavity 110 (also referred to as pawl cavity) is adapted to receive a pawl mechanism. For example, the second cavity 110 is adapted to receive a pawl carrier 114 and a first pawl 116 and a second pawl 118. As described above, the first cavity 108 and the second cavity 110 overlap or communicate to allow the first pawl 116 and the second pawl 118 to selectively move to engage and disengage with drive gear 112.

[0016] When the component is assembled into the cavity 106 of the head 102, a cover plate 122 is coupled (e.g., via a fastener 124) to the head 102 to cover or close the cavity 106. The fastener 124 extends through a corresponding fastener hole 126 in the head 102 and into a fastener hole 128 in the cover plate. The cover plate 122 also includes a circular opening 130 through which the drive post 132 of the drive gear 112 protrudes for operably engaging with a socket or workpiece. The circular opening 130 may also define a support surface for the drive post 132 to retain and position the drive gear 112.

[0017] The drive gear 112 has a generally circular gear portion and a drive column or flange 132. The gear portion has gear teeth 134 on its circumferential surface that engage with the pawl teeth of the first pawl 116 and the second pawl 118. The drive column or flange 132 may be a drive block extending from the gear portion. The gear teeth 134 of the drive gear 112 are arranged or housed in a drive cavity 108, and the drive column or flange 132 extends out of the drive cavity 108 (through a circular opening 130 in the cover plate 122). A braking mechanism 136 may also be incorporated into the drive column 132. The braking mechanism 136 may include a spring-biased ball for retaining a socket and other adapters that may be arranged on or connected to the drive column 132.

[0018] A pawl carrier 114 is disposed or received in a pawl cavity 110. The pawl carrier 114 includes a side or rear side facing away from the drive cavity 108, the side including a first brake cavity 138 and a second brake cavity 140, and a protrusion 142 between the first brake cavity 138 and the second brake cavity 140. The first brake cavity 138 and the second brake cavity 140 are adapted to receive a braking mechanism that provides a definite indication of the selection of a first rotational drive direction and a second rotational drive direction. The braking mechanism may include a ball 144 and a spring 146 disposed in an opening 148 in a sidewall formed by the pawl cavity 110, such that the ball 144 is outwardly biased by the spring 146, at least partially entering the pawl cavity 110. During operation, the pawl carrier 114 can be rotated via rotation of the reversing lever 120 to select either the first rotational drive direction or the second rotational drive direction. For example, when ball 144 is in the first braking cavity 138, the first rotational driving direction is selected; when ball 144 is in the second braking cavity 140, the second rotational driving direction is selected.

[0019] The pawl carrier 114 includes a side or front side facing the drive cavity 108, which includes a first pawl cavity 150 and a second pawl cavity 152, and a protrusion 154 between the first pawl cavity 150 and the second pawl cavity 152. The first pawl cavity 150 and the second pawl cavity 152 are adapted to receive corresponding first pawls 116 and second pawls 118. The pawl carrier also includes a first recessed shoulder 156 and a second recessed shoulder 158, and a first recess or groove 160 and a second groove or groove 162 adjacent to the corresponding first pawl cavity 150 and the second pawl cavity 152. The thickness or height of the first recessed shoulder 156 and the second recessed shoulder 158 is less than the thickness or height of the body of the pawl carrier 114. The first recess or groove 160 and the second groove or groove 162 are adjacent to the corresponding first recessed shoulder 156 and second recessed shoulder 158, and provide a thickness or height less than the thickness or height of the first recessed shoulder 156 and the second recessed shoulder 158 for a portion of the body of the pawl carrier 114.

[0020] The first pawl 116 and the second pawl 118 respectively include first pawl teeth 164 and 166 on a first side of the pawls 116 and 118, which selectively engage with gear teeth 134. The first pawl 116 and the second pawl 118 also include a first rear side 168 and a second rear side 170 opposite to the pawl teeth 164 and 166, respectively. The first pawl 116 and the second pawl 118 also include a first hook-shaped protrusion 172 and a second hook-shaped protrusion 174, each having a first protrusion 176 and a second protrusion 178, respectively. The first hook-shaped protrusion 172 and the second hook-shaped protrusion 174 extend outward from the first rear side 168 and the second rear side 170 opposite to the pawl teeth 164 and 166, respectively. The corresponding first hook-shaped protrusion 172 and the second hook-shaped protrusion 174 may also be in the same plane formed by the top surfaces of the corresponding first pawl 116 and the second pawl 118. The first protrusion 176 and the second protrusion 178 extend downward from the first hook-shaped protrusion 172 and the second hook-shaped protrusion 174, respectively. For example, the first protrusion 176 and the second protrusion 178 extend away from the cover plate 122 and toward the pawl support 114.

[0021] A first pawl 116 and a second pawl 118 are disposed or received in a pawl cavity 110 and are operatively connected to a pawl carrier 114. For example, the first pawl 116 is disposed in the pawl cavity 110, a first rear side 168 is disposed in a first pawl recess 150 of the pawl carrier 114, a first hook-shaped protrusion 172 extends over a first recessed shoulder 156 of the pawl carrier 114, and a first protrusion 176 extends into a first groove 160 of the pawl carrier 114. Similarly, the second pawl 118 is disposed in the pawl cavity 110, a second rear side 170 is disposed in a second pawl recess 152 of the pawl carrier 114, a second hook-shaped protrusion 174 extends over a second recessed shoulder 158 of the pawl carrier 114, and a second protrusion 178 extends into a second groove 162 of the pawl carrier 114. The engagement of the first protrusion 176 with the first groove 160 and the engagement of the second protrusion 178 with the second groove 162 also allow the first pawl 116 and the second pawl 118 to rotate in the first pawl cavity 150 and the second pawl cavity 152, respectively. This allows the corresponding first pawl 116 and second pawl 118 to maintain proper orientation when the drive gear 112 is selectively engaged.

[0022] The reversing lever 120 includes a lever portion 180 and a protrusion 182. The lever portion 180 is disposed through an opening 184 in the head 102 and is positioned on the outer side of the head 102 to provide manual operation for the user to select the rotary drive direction. The protrusion 182 engages with a correspondingly shaped opening in the pawl carrier 114 to provide co-rotation of the pawl carrier 114 and the reversing lever 120 for manually selecting a first rotary drive direction or a second rotary drive direction.

[0023] During operation, the reversing lever 120 can be manually operated to select either the first rotary drive direction or the second rotary drive direction. For example... Figure 2 As shown, a first rotational drive direction is selected. When the first rotational drive direction is selected, the first pawl tooth 164 of the first pawl 116 engages with the gear tooth 134. The ball 144 is also located in the first brake cavity 138 of the pawl support 114. The engagement of the second protrusion 178 of the second pawl 118 with the second groove 162 of the pawl support 114 also allows the second pawl 118 to rotate within the second pawl cavity 152, allowing the second pawl 118 to maintain the proper orientation for engaging the drive gear 112 when the second rotational direction is selected.

[0024] When the reversing lever 120 moves or rotates from the first rotation direction selection to select the second rotation drive direction, the rotation of the reversing lever 120 causes the pawl carrier 114 to rotate, causing the protrusion 142 of the pawl carrier 114 to overcome the bias of the spring 146 to press down or move the ball 144, allowing the protrusion 142 to move past the ball 144 and causing the ball 144 to engage the second brake cavity 140. The rotation of the pawl carrier 114 causes the first pawl 116 to be pulled or moved away from the drive gear 112 (via the engagement of the first protrusion 176 of the first pawl 116 with the first groove 160 of the pawl carrier 114), and the first pawl tooth 164 moves out of engagement with the gear tooth 134. The engagement of the first protrusion 176 of the first pawl 116 with the first groove 160 of the pawl carrier 114 also allows the first pawl 116 to rotate within the first pawl cavity 150, allowing the first pawl 116 to maintain the proper orientation for engaging the drive gear 112 when the first rotation direction is selected again. The rotation of the pawl carrier 114 also causes the second pawl 118 to be pushed or moved toward the drive gear 112 (via the engagement of the second protrusion 178 of the second pawl 118 with the second groove 162 of the pawl carrier 114), and the second pawl tooth 166 moves to engage with the gear tooth 134.

[0025] The engagement of the corresponding first protrusions 176 and 178 of the first pawl 116 and the second pawl 118 with the corresponding first grooves 160 and 162 of the pawl carrier 114 allows the first pawl 116 and the second pawl 118 to move to facilitate selection of either a first rotational drive direction or a second rotational drive direction. This engagement also allows non-engaged pawls (i.e., pawls not engaged with the drive gear) to maintain proper orientation for engaging the drive gear 112 when moved to engage the drive gear 112.

[0026] Although the ratchet wrench describes a pawl mechanism, the pawl mechanism can also be incorporated into other ratchet wrenches, such as ratchet box wrenches and power ratchet tools.

[0027] As used herein, the term "connection" and its functional equivalents are not necessarily limited to a direct mechanical link between two or more components. Rather, the term "connection" and its functional equivalents are intended to refer to any direct or indirect mechanical, electrical, or chemical connection between two or more objects, features, workpieces, and / or environmental substances. In some examples, "connection" also indicates that one object is integral with another.

[0028] The matters set forth in the above description and accompanying drawings are provided by way of illustration only and are not intended to be limiting. While 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 defined in the claims when viewed appropriately from the perspective of prior art.

Claims

1. A pawl mechanism for a ratchet tool, the ratchet tool having a drive gear with gear teeth, the pawl mechanism comprising: A pawl support includes a first pawl cavity, a first groove, and a first recessed shoulder arranged adjacent to the first groove; as well as A first pawl, disposed in a first pawl cavity, includes a first pawl tooth that can selectively engage with the gear teeth to select a first rotational drive direction. The first pawl includes a first protrusion extending away from the first pawl tooth and over the first recessed shoulder, and a first projection extending from the first protrusion into the first groove.

2. The ratchet mechanism according to claim 1, wherein, The thickness of the first recessed shoulder is less than the thickness of the main body of the pawl support.

3. The ratchet mechanism according to claim 1, wherein, The pawl support includes a second pawl cavity and a second groove.

4. The ratchet mechanism according to claim 3, wherein, It also includes a second pawl, which is disposed in the second pawl cavity and includes a second pawl tooth that can selectively engage with the gear teeth to select a second rotational drive direction. The second pawl includes a second protrusion extending away from the second pawl tooth and a second projection extending from the second protrusion into the second groove.

5. The ratchet mechanism according to claim 4, wherein, The rotation of the pawl carrier from selecting the first rotational drive direction to selecting the second rotational drive direction causes the pawl carrier to move the first protrusion and the first pawl away from the drive gear and disengage the first pawl tooth from the gear tooth, and causes the pawl carrier to move the second protrusion and the second pawl toward the drive gear and engage the second pawl tooth with the gear tooth.

6. The ratchet mechanism according to claim 4, wherein, The pawl support includes a second recessed shoulder adjacent to the second groove, and the second protrusion extends over the second recessed shoulder.

7. The ratchet mechanism according to claim 6, wherein, The thickness of the second recessed shoulder is less than the thickness of the main body of the pawl support.

8. A ratchet tool, comprising: The ratchet head has a drive chamber and a pawl chamber; A drive gear, which is arranged in the drive cavity and includes gear teeth; A pawl support member is arranged in the pawl cavity and includes a first pawl cavity and a second pawl cavity facing the drive gear, a first groove and a second groove, a first recessed shoulder arranged adjacent to the first groove, and a second recessed shoulder arranged adjacent to the second groove. A reversing lever, which is connected to the pawl carrier and is movable, is used to select either a first rotational drive direction or a second rotational drive direction. A first pawl is disposed in the pawl cavity and in the first pawl recess. The first pawl includes a first pawl tooth that can selectively engage with the gear tooth when the first rotational drive direction is selected. The first pawl includes a first protrusion extending away from the first pawl tooth and over the first recessed shoulder, and a first protrusion extending from the first protrusion and into the first recess. as well as The second pawl is disposed in the pawl cavity and in the second pawl recess. The second pawl includes a second pawl tooth that can selectively engage with the gear tooth when the second rotational drive direction is selected. The second pawl includes a second protrusion extending away from the second pawl tooth and over the second recessed shoulder, and a second protrusion extending from the second protrusion and into the second recess.

9. The ratchet tool according to claim 8, wherein, The thickness of the first recessed shoulder is less than the thickness of the main body of the pawl support.

10. The ratchet tool according to claim 8, wherein, The thickness of the second recessed shoulder is less than the thickness of the main body of the pawl support.

11. The ratchet tool according to claim 8, wherein, When the first rotational drive direction is selected, the first pawl tooth is engageable with the gear tooth, and the second pawl tooth is arranged away from the gear tooth.

12. The ratchet tool according to claim 8, wherein, When the second rotational drive direction is selected, the second pawl tooth is engageable with the gear tooth, and the first pawl tooth is arranged away from the gear tooth.

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