Patent Application
20190193251
The present invention relates to an attachment assembly for being connected with a hand tool so as to transfer torque to objects.
The conventional attachment to be used in conjunction with a ratchet wrench know to applicant is disclosed in U.S. Pat. No. 4,279,314, and comprises a housing having an internal compartment. An access opening is formed within the housing and connected with the internal compartment. A primary drive gear is rotatably mounted within the internal compartment. The primary drive gear has a socket opening centrally located within the primary drive gear. The socket opening connects with the access opening. A secondary drive gear is rotatably mounted within the internal compartment. The secondary drive gear is operatively connected through an idler gear to the primary drive gear. A spring assembly is connected to both the primary and the secondary drive gears. The spring assembly is windable by rotating the socket opening. The socket opens to connect with a socket plug. The spring assembly causes rotation of the socket plug. A movable pawl is mounted on the housing and located within the internal compartment. The movable pawl is movable between an engaging position and a disengaging position. The engaging position connects the movable pawl with one of the drive gears and prevents rotation of the socket opening by the spring assembly.
However, the attachment is a rectangular part and cannot be bent an angle when the polygonal shaped opening is connected with an object, so that the combination of the wrench and the attachment cannot be rotated in a small area. Besides, there are the idler gear, the secondary driving gear and the socket sleeve received in the attachment which has a limited room, so that when the wrench rotates the socket plug, the significant torque cannot be generated by the attachment itself. The attachment has to contact against the wrench by the pin. Furthermore, the length of the attachment is limited, when the polygonal shaped opening is connected with an object, only a limited torque is generated and this restricts the range of use of the attachment.
The present invention intends to provide an attachment unit for being connected with a hand tool so as to transfer large torque to objects.
The present invention relates to an attachment assembly for being connected with a hand tool, and comprises an active unit, a passive unit and a shaft. The active unit includes a first base and a first cover. A front wheel, a middle wheel and a rear wheel are rotatably received in a space between the first base and the first cover in sequence. The front, middle and rear wheels are engaged with each other. The passive unit includes a second base and a second cover. A first wheel and a second wheel are rotatably received in a space between the second base and the second cover. The first and second wheels are engaged with each other. The shaft pivotably connects the active unit and the passive unit which is pivotably connected to the active unit.
The primary object of the present2invention is to provide an attachment assembly for being connected with a hand tool, wherein the active and passive units are pivotable relative to each other. The engagement between the front, rear, middle, first and second wheels provides features for different work tasks.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.
Referring to
The active unit 10 comprises a first base 11 and a first cover 15 which is mounted to the first base 11. Each of the first base 11 and the first cover 15 has a front end and a rear end. A front wheel 12, a middle wheel 14 and a rear wheel 13 are rotatably received in the space between the first base 11 and the first cover 15 in sequence. The first base 11 has a front recess 111, a middle recess 112 and a rear recess 113. The front recess 111 has a front pivotal hole 1111 defined through the bottom thereof. A first opening 1121 is defined in communication between the front and middle recesses 111, 112. The rear recess 113 opens to the rear end of the first base 11. A second opening 1131 is defined in communication between the middle and rear recesses 112, 113. The rear recess 113 has a rear pivotal hole 1132 defined through the bottom thereof. A first mounting hole 114 is defined through the front end of the first base 11 such that the front recess 111 is located between the first mounting hole 114 and the middle recess 112. The first base 11 includes four even-spaced locking holes 115.
The front wheel 12, the middle wheel 14 and the rear wheel 13 are respectively and rotatably received in the front recess 111, the middle recess 112 and the rear recess 113. The front wheel 12, the middle wheel 14 and the rear wheel 13 have the same diameter. Each of the front wheel 12, the middle wheel 14 and the rear wheel 13 has teeth 121/131/141 defined in an outside thereof. A polygonal engaging portion 122 is defined centrally in the front wheel 12. The teeth 121 of the front wheel 12 are engaged with the teeth 141 of the middle wheel 14 via the first opening 1121. The teeth 141 of the middle wheel 14 are engaged with the teeth 131 of the rear wheel 13 via the second opening 1131. The rear wheel 13 has an axial hole 132 defined centrally therethrough. The middle wheel 14 includes a first receiving portion 142 and an annular groove 143 located around the first receiving portion 142. A ring-shaped resilient member 144 is engaged with the annular groove 143.
The first cover 15 has two bores 151, 152 respectively located close to the front end and the rear end of the first cover 15. The two bores 151, 152 are respectively located corresponding to the front recess 111 and the rear recess 113. The front wheel 12 is rotatably engaged between the front pivotal hole 1111 and the bore 151 located close to the front end of the first cover 15. The engaging portion 122 and the axial hole 132 are respectively exposed. The rear wheel 13 is rotatably engaged between the rear pivotal hole 1132 and the bore 152 located close to the rear end of the first cover 15. The first cover 15 has a second mounting hole 154 defined through the front end thereof. The first and second mounting holes 114, 154 are located corresponding to each other and have the same shape. The first base 11 and the first cover 15 each have even-spaced locking holes 115, 155. Multiple rivets 16 are riveted through the locking holes 115, 155 to connect the first base 11 and the first cover 15. The first cover 15 covers up the middle wheel 14. The ring-shaped resilient member 144 is engaged with the annular groove 143 and contacts the first cover 15 so that when the middle wheel 14 is rotated, a damper is generated by the ring-shaped resilient member 144.
The passive unit 20 includes a second base 21 and a second cover 210 which is mounted to the second base 21. A first wheel 22 and a second wheel 23 are rotatably received in the space between the second base 21 and the second cover 210. The teeth 221 of the first wheel 22 is engaged with teeth 231 of the second wheel 23 and teeth 131 of the rear wheel 13.
The second base 21 has a recessed area 214, a first recess 211 and a second recess 212 defined therein. A third opening 2111 is defined in communication between the recessed area 214 and the first recess 211. The second recess 212 has a bore 213 defined through the bottom thereof. A fourth opening 2121 is defined in communication between the first recess 211 and the second recess 212. The rear end of the active unit 10 is rotatably located in the recessed area 214. The rear recess 113 of the active unit 10 communicates with the first recess 211 via the third opening 2111. The first wheel 22 has a circular second receiving portion 222, and the second wheel 23 has a polygonal engaging portion 232. The recessed area 214 has a bore 215 defined through the bottom thereof. The first and second wheels 22, 23 are respectively and rotatably received in the first and second recesses 211, 212. The first wheel 22 is engaged with the rear wheel 13 via the third opening 2111. The second wheel 23 is engaged with the first wheel 22 via the fourth opening 2121. The second wheel 23 is rotatably engaged between the bore 213 of the second recess 212 and another bore 213 of the second cover 210. Multiple rivets 24 extend through the locking holes 217 to connect the second cover 210 to the second base 21.
A shaft 30 extends through the bore 215 of the recessed area 214 and the axial hole 132 of the rear wheel 13 so that the active unit 10 and the passive unit 20 are pivotable about the shaft 30 to adjust the angle between the active unit 10 and the passive unit 20. The shaft 30 has a head 31 on the top end thereof, and a groove 32 is defined in the lower end thereof. A clip 35 is engaged with the groove 32. The head 31 and the clip 35 are respectively received in the two respective enlarged recesses 216 so as to restrict the shaft 30 from dropping from the bore 215 and the axial hole 132.
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In another embodiment, the groove 32 is a threaded portion which is connected with the clip 35. The engaging portion 232 is a rectangular protrusion.
The advantages of the present invention are that the active and passive units 10, 20 are pivotably connected to each other. The front wheel 12, the middle wheel 14, the rear wheel 13, the first wheel 22 and the second wheel 23 are co-rotated. Therefore, the operational status can be easily adjusted to meet different work tasks as shown in
While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.
