1. Field of Invention
The present invention relates to a ratchet wrench and, more particularly, to a telescopic ratchet wrench.
2. Related Prior Art
A ratchet wrench includes a handle, a head formed at an end of the handle, and a ratchet-like mechanism placed in the head. The ratchet-like mechanism includes a non-circular tongue for insertion in a corresponding bore made in a socket. The socket is engaged with a nut or a head of a threaded bolt. By operating the combination of the ratchet wrench with the socket, the nut or the threaded bolt is tightened or loosened.
Conventionally, the handle is made with a fixed length. By exerting a force on the handle, a larger torque is produced if the handle extends longer. However, it is less convenient to operate the one-way wrench if the handle extends longer.
The handle can be made in a telescopic configuration that includes a shank, a grip movably connected to the rod, and a positioning unit for positioning the grip on the shank. The positioning unit is supported on the grip and made with a portion for engagement with the shank. The positioning unit is switched in a longitudinal direction of the grip between a locking position and a releasing position. The switching of the positioning unit is however complicated.
Moreover, it is a gap between the shank and the grip. The gap could be too small to smoothly move the grip on the shank. The gap could be too large to keep the grip in line with the shank. It requires high precision to make the shank and the grip so that the gap is properly sized. To reach high precision, a complicated process that includes quite a few steps must be run. Such a complicated process takes a lot of time and costs a lot of money.
Moreover, the ratchet wrench is inevitably dropped onto the ground or a floor from time to time. The ratchet wrench and/or the ground or floor might get damaged.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.
It is the primary objective of the present invention to provide a ratchet wrench with a reliable, smooth telescopic handle.
To achieve the foregoing objective, the telescopic handle includes a shank, a tube and a positioning unit. The shank includes a longitudinal groove and bores located in the longitudinal groove. The tube is movably supported on the shank and includes at least one aperture. A ring is placed between the shank and the tube. The positioning unit includes a shell, a button, a spring and a ball. The shell is supported on the tube and formed with a pocket. The button is movably inserted in the pocket and includes a shallow recess and a deep recess. The ball includes a first portion movable along the longitudinal groove and a second portion placed against the button. The first portion of the ball enters one of the bores via the aperture when the spring pushes the button into an upper position to place the second portion of the ball in the shallow recess. The first portion of the ball can escape from any of the bores when the button is pushed to allow the second portion of the ball to enter the deep recess.
Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings.
The present invention will be described via detailed illustration of the preferred embodiment referring to the drawings wherein:
Referring to
The tube 20 includes an aperture 21. The aperture 21 is made with a diameter identical to that of the bores 12.
The positioning unit 30 includes a shell 31, two screws 32, a decorative strip 33, a button 34, a spring 35 and a ball 36. The shell 31 includes a tunnel 311, a cavity 312, two screw holes 313, a pocket 314, and an internal annular groove 317. The tunnel 311 is in communication with the screw bores 313, the pocket 314 and the internal annular groove 317. The tunnel 311 extends horizontally while the pocket 314 extends horizontally. The cavity 312 is made in an external side of the shell 31. The screw bores 313 are located in the cavity 312.
Referring to
The button 34 includes a head 341, a body 342 and a shoulder (not numbered) formed between the head 341 and the body 342. The head 341 is made with a diameter larger than that of the body 342. The body 342 is made with a shallow recess 343 and a deep recess 344. The shallow recess 343 is in communication with the deep recess 344.
The cushioning unit 60 includes a grip 61, a knob 62, a screw 63 and a ring 64. The grip 61 includes an internal disc 611. The internal disc 611 includes a screw hole (not numbered) centrally made therein and an aperture 613 eccentrically made therein.
The knob 62 includes a disc (not numbered) formed at an end. The disc includes an aperture (not numbered) centrally made therein and another aperture 621 eccentrically. The aperture 621 is made with a diameter identical to that of the aperture 613.
Two rings 40 are placed in the annular grooves 123 before the tube 20 is movably supported on the shank 12. The aperture 21 is aligned with the longitudinal groove 121 as shown in
A ring 50 is placed in the internal annular groove 317. Then, the shell 31 is placed on the tube 20 so that the tube 20 extends throughout the tunnel 311 as shown in
The button 34 is inserted in the pocket 314. The head 341 of the button 34 is placed in the upper portion 316 of the pocket 314 while the body 342 of the button 34 is placed in the lower portion 315 of the pocket 314. The spring 35 is located between the shoulder of the button 34 and the shoulder of the pocket 314. Thus, button 34 is biased upwards relative to the shell 31 by the spring 35.
The grip 61 is movably supported on the tube 20. The knob 62 is rotationally connected to the grip 61 by inserting the screw 63 in the screw hole of the disc 611 of the grip 61 through the central aperture of the knob 62. The ring 64 is placed between the disc 611 of the grip 61 and the knob 62. The ring 64 is placed in a cavity (not numbered) around and in communication with the aperture 613.
The telescopic handle 10 can be switched between a shrunk position as shown in
The button positioning unit 30 can be maneuvered to allow the telescopic handle 10 to enter the shrunk position, the extended position or any intermediate position. These positions are determined by the bores 122.
Referring to
Referring to
Referring to
With the air trapped in the space 612, the shank 12, the tube 20 and the grip 61 together perform like a pneumatic cushion that can cushion an impact on the ratchet wrench 100 when the ratchet wrench 100 falls onto the ground as shown in
Advantageously, the arrangement of the button 34 in the shell 31 enables a user to operate the positioning unit 30 instinctively. Moreover, the rings 40 and 50 guarantee smooth movement of the tube 20 on the shank 12. In addition, the cushioning unit 60 cushions and protects the ratchet wrench 100 in a case where the ratchet wrench 100 is dropped onto the ground or a floor by accident.
The present invention has been described via the detailed illustration of the preferred embodiment. Those skilled in the art can derive variations from the preferred embodiment without departing from the scope of the present invention. Therefore, the preferred embodiment shall not limit the scope of the present invention defined in the claims.
Number | Name | Date | Kind |
---|---|---|---|
6959629 | Hsien | Nov 2005 | B2 |
7188553 | Pryor | Mar 2007 | B1 |
7434495 | Lin | Oct 2008 | B2 |
7497149 | Lin | Mar 2009 | B2 |
8266989 | Hu | Sep 2012 | B2 |
8297155 | Hu | Oct 2012 | B2 |
20070186730 | Chen | Aug 2007 | A1 |
20090090224 | Lin | Apr 2009 | A1 |
Number | Date | Country | |
---|---|---|---|
20150273680 A1 | Oct 2015 | US |