Patent Application
20190337128
The present invention relates to a ratchet tool and, particularly, to a pawl control mechanism of a ratchet tool and, more particularly, to an elastic member of the pawl control mechanism.
TW Pat. No. 408653 shows a ratchet tool with a ratchet mechanism including a gear wheel and a pawl in tooth engagement with the gear wheel. The pawl is selectively movable between a position in which the gear wheel is allowed to rotate clockwise and prevented from rotating counterclockwise, a position in which the gear wheel is allowed to rotate counterclockwise and prevented from rotating clockwise, and a position in which the gear wheel is prevented from rotating either clockwise or counterclockwise. Furthermore, the pawl is actuated by a pawl control mechanism and changes positions upon operation of the pawl control mechanism. The pawl control mechanism includes a control input, an engaging pin, and an elastic member. The engaging pin has one end retained on the control input and another end retained on the pawl respectively. The elastic member has one end retained on the control input and another end retained on the engaging pin and. The engaging pin is urged by the elastic member to push the pawl toward the gear wheel.
It is noted that rotations of the gear wheel are often not smooth and the teeth of pawl and the gear wheel are not engaged properly.
The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art.
According to the present invention, a ratchet tool includes a head portion, a ratchet mechanism, and a pawl control mechanism. The head portion has a first second and third compartment communicated with one another, and the third compartment is located between the first and second compartments. The ratchet mechanism includes a gear wheel and a pawl engaged with the gear wheel in tooth engagement. The gear wheel is rotatably mounted on the head portion and positioned in the first compartment. The gear wheel includes a plurality of first teeth disposed circumferentially on an outer periphery thereof. The pawl is movably mounted on the head portion and is positioned in the third compartment. The pawl includes a plurality of second teeth disposed on a first side thereof and engaged with the plurality of first teeth. The pawl control mechanism includes a pusher and an elastic member urging the pusher. The pusher includes a first end against the pawl and pushes the pawl toward the gear wheel and a second end against the elastic member. The elastic member is selectively compressed by the pusher. The elastic member includes at least one limiting portion of a first internal diameter at a first end thereof and against the second end of the pusher. The elastic member includes a plurality of compressible portions and the compressible portion adjacent to the at least one limiting portion has a second internal diameter. The first internal diameter is less than the second internal diameter.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure. The abstract is neither intended to define the invention, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
Other objectives, advantages, and new features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanied drawings.
As shown in
A ratchet mechanism 20 includes a gear wheel 21 and a pawl 30 engaged with the gear wheel 21 in tooth engagement. The gear wheel 21 is rotatably mounted on the head portion 10 and positioned in the first compartment 11. The gear wheel 21 includes a plurality of first teeth 211 disposed circumferentially on an outer periphery thereof. The pawl 30 is movably mounted on the head portion 10 and is positioned in the third compartment 13. The pawl 30 includes a plurality of second teeth 311 disposed on a first side 31 thereof and engaged with the plurality of first teeth 211. The gear wheel 21 includes a protrusion 25 extending therefrom. The gear wheel 21 and the protrusion 25 include an orifice 26 extending therein. The orifice 26 has a first section surrounded by the plurality of the first teeth 211 and a second section extending in the protrusion 25 respectively. The protrusion 25 includes an aperture 212 extending radially from the orifice 26. The aperture 212 includes a detent ball 24 movably disposed therein. The orifice 26 includes a shaft 22 movably disposed therein. The shaft 22 is urged by the biasing member 23. The shaft 22 includes recesses of different depths and the detent ball 24 is selectively disposed on the recesses in response to movement of the shaft 22.
A pawl control mechanism 40 includes a pusher 41 and an elastic member 42 urging the pusher 41. The pusher 41 includes a first end 411 against the pawl 30 and pushes the pawl 30 toward the gear wheel 21 and a second end 412 against the elastic member 42. The first end of the pusher 41 is against a second side 32 of the pawl 30. Specifically, the second side 32 includes a concave section and the first end of the pusher 41 is retained in the concave section. The elastic member 42 is selectively compressed by the pusher 41. The elastic member 42 includes at least one limiting portion 421 of a first internal diameter D421 at a first end thereof and against the second end 412 of the pusher 41. Preferably, the at least one limiting portion 421 includes two limiting portions 421 at opposite ends of the elastic member 42. The second end of the pusher 41 has a size small than the first internal diameter of the limiting portion 421 of the pusher 41. The at least one limiting portion 421 is in the form of a loop. The elastic member 42 also includes a plurality of compressible portions 422. Each of the plurality of compressible portions 422 is in the form of a loop. The compressible portion 422 adjacent to the at least one limiting portion 421 extends from a distal end of the at least one limiting portion 421. The compressible portion 422 adjacent to the at least one limiting portion 421 has a length of circumference radially spaced from a length of circumference of the at least one limiting portion 421. The at least one limiting portion 421 includes a section 423 partially contacted with the compressible portion 422 adjacent to the at least one limiting portion 421. The plurality of compressible portions 422 is connected with one another in series and aligned axially along an axis L and has a pitch between two adjacent compressible portions 422. The compressible portion 422 adjacent to the at least one limiting portion 421 has a second internal diameter D422. The first and second internal diameters D421 and D422 have a same end point. The first internal diameter D421 is less than the second internal diameter D422. Furthermore, the ratio between the first internal diameter D421 and the second internal diameter D422 is in a range between 0.5 and 0.9.
A control input 50 is movably mounted on the head portion 10 and positioned in the second compartment 12. The pusher 41 is engaged with and includes the first end 411 movably against the pawl 30 in response to movement of the control input 50. The control input 50 includes a hole 51 extending therein. The hole 51 is a through hole. The hole 51 has a small section 511 and a large section 512 aligned axially. An internal diameter D512 of the large section 512 is greater than an internal diameter D511 of the small section 511. The hole 51 forms a shoulder 513 extending radially between peripheries of the small and large sections 511 and 512. The pusher 41 and the elastic member 42 are disposed in the hole 51. The elastic member 42 includes a second end through the hole 51 and against a wall 121 of the second compartment 12.
In view of the forgoing, the pushers 41 and 41a and the at least one limiting portion 421 of the elastic member 42 are flatly contacted with each other to maintain the pushers 41 and 41a in a stable path. The at least one limiting portion 421 also prevents the pushers 41 and 41a from dropping into the space of each of the plurality of the compressible portions 422.
The foregoing is merely illustrative of the principles of this invention, and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 107115373 | May 2018 | TW | national |
