Ratchet tool with improved pawl
11331774 · 2022-05-17
Assignee
Inventors
Cpc classification
International classification
Abstract
A ratchet tool having a head having a first cavity is adapted to receive a cover plate and a second cavity. An aperture extends between the first cavity and the second cavity. Disposed in the first cavity is a ratchet gear and a pawl. A selector switch disposed in the second cavity and moves the pawl between a first position and a second position. A retaining clip retains the selector switch in the second cavity. The retaining clip extends into the first cavity. The pawl includes a first extended portion and a second extended portion extending from a lower end of the pawl. At least a portion of the retaining clip is disposed between the first extended portion and the second extended portion. The first extended portion and the second extended portion contact the lower surface of the first cavity. An upper end of the pawl contacts the cover plate.
Claims
1. A ratchet tool comprising: a head including: a front side including a first cavity including a lower surface, wherein the first cavity is adapted to receive a cover plate; and a rear side including a second cavity, wherein the second cavity is in communication with the first cavity such that an aperture extends between the first cavity and the second cavity; a ratchet gear disposed in the first cavity, wherein the ratchet gear includes a plurality of gear teeth; a single-piece pawl disposed in the first cavity, wherein the pawl includes a plurality of pawl teeth configured to mechanically engage in a vertical alignment with the plurality of gear teeth of the ratchet gear, and the pawl is movable between: a first position in which the pawl is configured to transmit torque through the ratchet gear in a first rotational direction, and a second position in which the pawl is configured to transmit torque through the ratchet gear in a second, opposite rotational direction; a selector switch disposed in the second cavity and configured to move the pawl between the first position and the second position; and a retaining clip configured to retain the selector switch in at least the second cavity, wherein the retaining clip extends into the first cavity; wherein: the pawl includes a first extended portion and a second extended portion extending from a lower end of the pawl and defining a recess between the lower end of the pawl, the first extended portion, and the second extended portion, wherein the recess extends from a front end of the pawl to a rear end of the pawl; at least a portion of the retaining clip is disposed in the recess and between the first extended portion and the second extended portion; the first extended portion and the second extended portion contact the lower surface of the first cavity; and an upper end of the pawl contacts the cover plate.
2. The ratchet tool of claim 1, wherein the plurality of pawl teeth extend onto the first extended portion and the second extended portion.
3. The ratchet tool of claim 2, wherein the plurality of pawl teeth extend from the upper end of the pawl to respective lower ends of the first extended portion and second extended portion.
4. The ratchet tool of claim 1, wherein the pawl further comprises a notch including first depth in a lower portion of the notch and a second depth in an upper portion of the notch, wherein: the first depth is greater than the second depth; a limiting portion is disposed between the lower portion of the notch and the upper portion of the notch; the lower portion of the notch is configured to engage with a spring-loaded pusher extending from a driver portion of the selector switch; and the limiting portion prevents the spring-loaded pusher from springing out of the lower portion of the notch.
5. The ratchet tool of claim 1, wherein the contact between the first extended portion and the second extended portion with the lower surface of the first cavity, and the contact between the upper end of the pawl with the cover plate, maintains the vertical alignment between the pawl teeth and the gear teeth of the ratchet gear.
6. The ratchet tool of claim 1, further comprising a layer of grease between the first extended portion and the second extended portion and the lower surface of the first cavity, and between the upper end of the pawl and the cover plate.
7. A ratchet tool comprising: a head including: a front side including a first cavity including a lower surface, wherein the first cavity is adapted to receive a cover plate; and a rear side including a second cavity, wherein the second cavity is in communication with the first cavity such that an aperture extends between the first cavity and the second cavity; a ratchet gear disposed in the first cavity, wherein the ratchet gear includes a plurality of gear teeth; a single-piece pawl disposed in the first cavity, wherein the pawl includes a plurality of pawl teeth configured to mechanically engage in a vertical alignment with the plurality of gear teeth of the ratchet gear, and the pawl is movable between: a first position in which the pawl is configured to transmit torque through the ratchet gear in a first rotational direction, and a second position in which the pawl is configured to transmit torque through the ratchet gear in a second, opposite rotational direction; a selector switch disposed in the second cavity and configured to move the pawl between the first position and the second position; and a retaining clip configured to retain the selector switch in at least the second cavity, wherein the retaining clip extends into the first cavity; wherein: the pawl includes a recessed portion, including a recessed surface that is offset from a lower end of the pawl, wherein the recessed portion extends from a front end of the pawl to a rear end of the pawl; at least a portion of the retaining clip extends into the recessed portion of the pawl; the lower end of the pawl contacts the lower surface of the first cavity; an upper end of the pawl contacts the cover plate; and wherein the plurality of pawl teeth extend from the upper end of the pawl to the lower end of the pawl.
8. The ratchet tool of claim 7, wherein the pawl further comprises a notch including first depth in a lower portion of the notch and a second depth in an upper portion of the notch, wherein: the first depth is greater than the second depth; a limiting portion is disposed between the lower portion of the notch and the upper portion of the notch; the lower portion of the notch is configured to engage with a spring-loaded pusher extending from a driver portion of the selector switch; and the limiting portion prevents the spring-loaded pusher from springing out of the lower portion of the notch.
9. The ratchet tool of claim 7, wherein the contact between the lower end of the pawl with the lower surface of the first cavity and the upper end of the pawl with the cover plate, maintains the vertical alignment between the pawl teeth and the gear teeth of the ratchet gear.
10. The ratchet tool of claim 7, further comprising a layer of grease between the lower end of the pawl and the lower surface of the first cavity, and between the upper end of the pawl and the cover plate.
11. A single-piece pawl for a ratchet tool comprising: an upper end; a lower end; a front end; and a rear end; wherein: the pawl includes a plurality of pawl teeth positioned on the front end of the pawl that are configured to mechanically engage in a vertical alignment with a plurality of gear teeth of a ratchet gear; the pawl includes a first extended portion and a second extended portion extending from the lower end of the pawl and defining a recess between the lower end of the pawl, the first extended portion, and the second extended portion, wherein the recess extends from the front end of the pawl to the rear end of the pawl; at least a portion of a retaining clip of a selector switch is disposed in the recess and between the first extended portion and the second extended portion such that the first extended portion and the second extended portion contact a lower surface of a ratchet tool head cavity; and the upper end of the pawl contacts a ratchet tool cover plate.
12. The pawl of claim 11, wherein the plurality of pawl teeth extend onto the first extended portion and the second extended portion.
13. The pawl of claim 12, wherein the plurality of pawl teeth extend from the upper end of the pawl to respective lower ends of the first extended portion and second extended portion.
14. The pawl of claim 11, further comprising a notch including first depth in a lower portion of the notch and a second depth in an upper portion of the notch, wherein: the first depth is greater than the second depth; a limiting portion is disposed between the lower portion of the notch and the upper portion of the notch; the lower portion of the notch is configured to engage with a spring-loaded pusher extending from a driver portion of the selector switch; and the limiting portion prevents the spring-loaded pusher from springing out of the lower portion of the notch.
15. The pawl of claim 11, wherein the contact between the first extended portion and the second extended portion with the lower surface of the ratchet tool head cavity, and the contact between the upper end of the pawl with the ratchet tool cover plate, maintains the vertical alignment between the pawl teeth and the gear teeth of the ratchet gear.
16. A single-piece pawl for a ratchet tool comprising: an upper end; a lower end; a front end; and a rear end; wherein: the pawl includes a plurality of pawl teeth positioned on the front end of the pawl that are configured to mechanically engage in a vertical alignment with a plurality of gear teeth of a ratchet gear; the pawl includes a recessed portion on the lower end of the pawl, the recessed portion including a recessed surface that is offset from the lower end of the pawl, wherein the recessed portion extends from the front end of the pawl to the rear end of the pawl; at least a portion of the recessed portion is configured to receive at least a portion of a retaining clip of a selector switch such that the lower end of the pawl contacts a lower surface of a ratchet tool head cavity; the upper end of the pawl contacts a ratchet tool cover plate; and wherein the plurality of pawl teeth extend from the upper end of the pawl to the lower end of the pawl.
17. The pawl of claim 16, further comprising a notch including first depth in a lower portion of the notch and a second depth in an upper portion of the notch, wherein: the first depth is greater than the second depth; a limiting portion is disposed between the lower portion of the notch and the upper portion of the notch; the lower portion of the notch is configured to engage with a spring-loaded pusher extending from a driver portion of the selector switch; and the limiting portion prevents the spring-loaded pusher from springing out of the lower portion of the notch.
18. The pawl of claim 16, wherein the contact between the lower end of the pawl with the lower surface of the ratchet tool head cavity, and the contact between the upper end of the pawl with the ratchet tool cover plate, maintains the vertical alignment between the pawl teeth and the gear teeth of the ratchet gear.
Description
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
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(17) The foregoing summary, as well as the following detailed description of certain techniques of the present application, will be better understood when read in conjunction with the appended drawings. For the purposes of illustration, certain techniques are shown in the drawings. It should be understood, however, that the claims are not limited to the arrangements and instrumentality shown in the attached drawings. Furthermore, the appearance shown in the drawings is one of many ornamental appearances that can be employed to achieve the stated functions of the system.
DETAILED DESCRIPTION
(18) Parts Listing:
(19) TABLE-US-00001 Number Description 1 Ratchet tool 1′ Prior art ratchet tool 2 Handle 10 Head 10a Front side of head 10b Rear side of head 11 First cavity 11a Drive cavity 11b Pawl cavity 12 Second cavity 13 Lower surface of pawl cavity 14 Sidewall of pawl cavity 15 Circular recess 16 Aperture between first cavity and second cavity 17 Cover place recess 18 Cover plate screw apertures 20 Pawl 20′ Prior art pawl 21 Pawl teeth 22 Extended portion 23 Recessed portion 24 Notch 24a Upper portion of the notch 24b Lower portion of the notch 25 Limiting portion 30 Selector Switch 31 Lever portion 32 Retaining clip aperture 33 Retaining clip 34 Driver portion 35 Pusher 36 Pusher aperture 37 Spring 40 Ratchet Gear 41 Gear teeth 42 Cylindrical body portion 43 Circumferential surface 44 Extended drive post 45 Bearing portion 50 Cover plate 51 Screw apertures 52 Screw 53 Circular bore
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(21) The first cavity 11 may be generally positioned on the front side 10a of the head 10 and include several portions for receiving and retaining the components therein. For example, first cavity 11 may include a generally large circular drive cavity 11a, for receiving the ratchet gear 40. The drive cavity 11a may further include a circular recess 15 for receiving a bearing portion 45 of the ratchet gear 40. The first cavity 11 may also include a pawl cavity 11b for receiving the pawl 20. The pawl cavity 11b may include a lower surface 13. The pawl cavity 11b may be slightly more recessed than the drive cavity 11a.
(22) The pawl 20 may include pawl teeth 21 located on a front end of the pawl 20. In one embodiment the pawl 20 may have first and second extended portions 22 extending from a lower end of the pawl 20. A recessed portion 23 may be generally located between the first and second extended portions 22. In another embodiment, the recessed portion 23 may be cut directly into a lower end of the pawl 20. The pawl may include a notch 24 on a rear end of the pawl 20.
(23) The ratchet gear 40 may have a generally cylindrical body portion 42 having gear teeth 41 (i.e., ratchet gearing) positioned on a circumferential surface 43. The ratchet gear 40 may also have an extended drive post 44. In one embodiment the extended drive post 44 is a drive square. The ratchet gear 40 may further include a bearing portion 45 to permit rotation of the ratchet gear 40 and assist in centering and retaining the ratchet gear 40 within the drive cavity 11a. As will be discussed in more detail below, the pawl teeth 21 engage with the gear teeth 41 to transfer torque the ratchet gear 40.
(24) A second cavity 12 may be generally positioned on the rear side 10b of the head 10. The second cavity 12 may receive and retain the selector switch 30. The second cavity 12 may at least partially overlap with the first cavity 11 such that an aperture 16 extends between the first cavity 11 and second cavity 12. The aperture 16 may allow communication between the first cavity 11 and second cavity 12. In one embodiment, a driver portion 34 of the selector switch 30 may extend at least partially through the aperture 16 into the first cavity 11. The selector switch 30 may be retained in the second cavity 11 and head 10 by a retaining clip 33. The retaining clip 33 may be disposed in a retaining clip aperture 32 located on the driver portion 34. When installed, the retaining clip 33 may overlap with the lower surface 13 of the first cavity 11 thereby preventing the selector switch 30 from falling out of the second cavity 12. The selector switch 30 may also include a pusher aperture 36 for receiving a spring 37 and pusher 35. The spring 37 may bias the pusher 35 outward from the pusher aperture 36. The spring loaded pusher 35 may engage with the pawl 20. Specifically, the spring-loaded pusher 35 may be biased outward by the spring 37 to engage with the notch 24 of the pawl 20.
(25) Once the ratchet tool 1 is assembled, a cover plate 50 may be secured to a cover plate recess 17 of the ratchet head 10 to cover the first cavity 11. The cover plate 50 may be secured by screws 52 that thread into screw apertures 18 positioned in the cover plate recess 17 of the ratchet head 10. The cover plate may include a circular bore 53 through which the extend drive post 44 projects for operative engagement with a working piece.
(26) As may be evident from the example ratchet head 10 shown in
(27) As is shown in
(28) Specifically, as is shown for example in
(29) Likewise, as is shown for example in
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(31) In contrast,
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(35) The pawl may have pawl teeth 21 positioned on the front end of the pawl 20. The pawl teeth 21 may be formed to mechanically engage with ratchet teeth 41. The pawl teeth 21 may cover the entire front end of the pawl 20 extending from the upper end of the pawl 20 to the lower end of the pawl 20. The pawl teeth 21 may extend onto the at least one extended portions 22. Thus, in such an embodiment the pawl teeth 21 span across a single continuous surface (i.e., front end of the pawl 20), including the front surface of the one or more extended portions 22. Such a configuration is advantageous because the total meshed area of the pawl teeth 21 is maximized yielding higher strength. Thus, by providing pawl teeth 21 on the entire height of the pawl 20, the interaction length (moment arm) is longer and there will be less stress on the pawl 20 during operation. The longer length of the pawl teeth 20 extending onto the extended portions 22 may also cause the pawl teeth 21 to align with higher accuracy.
(36) In one embodiment, the pawl 20 includes first and second extended portions 22. Greater or fewer number of extended portions 22 are possible. The pawl 20 may further include a recessed portion 23 positioned generally between the first and second extended portions 22. The height of the recessed portion 23 may be configured to be at least slightly greater than the height of a retaining clip 33. In such an embodiment, if the pawl 20 were positioned on a flat surface, for example lower surface 13, such that the first and second extended portions 22 contact the surface, a retention clip 33 could slide without interference in and out of recess portion 23.
(37) As was discussed above with reference to
(38) By stabilizing the pawl 20, the pawl 20 only engages with the ratchet gear 40 when the pawl 20 is completely positioned in either the first position or the second position as described above, yielding longer life. Additionally, the stabilization of the pawl 20 may cause the pawl teeth 21 and the gear teeth 41 to be consistently and properly vertically aligned so that both sets of teeth mesh fully. Such a vertical alignment prevents both the pawl teeth 21 and the gear teeth 41 from being damaged and/or rounded off.
(39) By contrast, a prior art pawl 20′ as pictured in
(40) While, the pawl depicted in
(41) Referring again to
(42) It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the novel techniques disclosed in this application. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the novel techniques without departing from its scope. Therefore, it is intended that the novel techniques not be limited to the particular techniques disclosed, but that they will include all techniques falling within the scope of the appended claims.