High Torsion Ratcheting Driver Handle

1. Field of the Invention

The invention relates to a screw driver handle, more particularly to a high torsion ratcheting driver handle.

2. Description of the Related Art

Referring to FIGS. 1 and 2, a conventional driver handle for a driver bit is shown to include an elongated body 1, a ratcheting mechanism 2, a turnable disc 6, a spring member 9, a selector cap 7 and a shank 8.

As illustrated, the elongated body 1 has an end portion formed with an inner annular wall 111A that extends in an axial direction to define an axial hole 112A which opens at the end portion. The ratcheting mechanism 2 includes an elongate ratcheting housing 201 disposed in the axial hole 112, and has an end wall formed with an axial bore 2a to receive a gear member 3 therein and two lateral pawl receiving holes 2b in communication with the axial bore 2a to receive left and right spring-biased pawl units 4, 5, respectively, therein such that the tooth portions 5a of the latter mesh with the gear member 3. The end wall of the ratcheting housing 201 further has two spring-retaining curved slots 2c formed therethrough. The gear member 3 defines a non-circular hole 3a that extends in the axial direction and that accommodates the shank 8 non-rotatably therein. The turnable disc 6 is disposed for turning around the axial direction in the clockwise and counterclockwise directions, and has a central hole for passage of the shank 8 and an axially extending tongue 6a that projects into the axial bore 2a of the ratcheting housing 201 to abut against the tooth portion of the right pawl unit 5 so as to the prevent engagement between the gear member 3 and the right pawl unit 5. Two end portions 9a of the spring member 9 extend in the axial direction through two insert holes 6c of the turnable disc 6 and engage the curved slots 2c of the ratcheting housing 201 to provide a resilient retarding force during turning of the turnable disc 6. The selector cap 7 has a central hole for passage of the shank 8, and a plurality of angularly spaced plugs 7a inserted into socket holes 6b of the turnable disc 6 so as to transmit turning of the selector cap 7 to the turnable disc 6.

A disadvantage of the conventional ratcheting driver handle resides in that the spring members 4 of the pawl units 5 must be maintained at an appropriate tension force because, in case the tension is considerable strong, the user must exert a considerable force to turn the elongated body 1 in the clockwise direction in order to cause idle rotation of the ratcheting housing 201 relative to the gear member 3. In addition, because only one of the pawl units 5 is engaged to the gear member 3, thereby providing a poor torque on a workpiece when the elongated body 1 is turned about the axial direction in the counterclockwise direction in order to perform a tightening operation.

Therefore, the object of this invention is to provide a ratcheting driver handle for a driver bit which is clear of the aforementioned disadvantages that are generally associated with the conventional ratcheting driver handle.

Accordingly, a ratcheting driver handle for a driver bit of this invention includes an elongated body, a ratcheting mechanism, a spring member, a retaining member, first and second barrier members, and a shank. The elongated body has an end portion formed with an inner annular wall that extends in an axial direction to define an axial hole. The axial hole opens at the end portion. The ratcheting mechanism is disposed in the axial hole, and includes a gear member that is disposed to be coaxial and rotatable relative to the axial hole. The gear member has a coupling end adapted to engage the shank of the driver bit, and a rim portion disposed around the axial direction. The rim portion is provided with a tooth member that is spaced apart from the annular wall in a radial direction to define an annular chamber therebetween. The ratcheting mechanism further includes a pawl member disposed in the annular chamber, and having a fulcrum point lying in a fulcrum line parallel to the axial direction, and first and second tooth portions disposed at two sides of the fulcrum line opposing each other in such a manner that one of the first and second tooth portions engages with the tooth member when the fulcrum point is shifted between first and second positions along a line parallel to a chord line relative to the gear member. The spring member includes a mounting end secured to the fulcrum point, and a free end that extends angularly from the mounting end around the gear member. The free end is slidably retained in first and second anchored points that are disposed angularly on the inner annular wall when the fulcrum point is shifted between the first and second positions, respectively. The retaining member is disposed on the inner annular wall to slidably anchor the free end at, in a clockwise direction, a downstream location which corresponds to the second anchored point, and an upstream location which corresponds to the first anchored point. The tooth member is ratcheted by the second tooth portion in a counterclockwise direction against a first biasing action of the spring member generated when the free end is at the second anchored point and the mounting end is at the second position. The tooth member is ratcheted by the first tooth portion in the clockwise direction against a second biasing action generated when the free end is at the first anchored point and the mounting end is at the first position. The first and second barrier members are disposed respectively to hinder the disengaged one of the first and second tooth portions from moving away from the tooth member in the radial direction when one of the first and second tooth portions is brought to engage the tooth member by shifting the fulcrum point between the first and second positions, thereby pulling or pushing the mounting end so as to drag or to move over the free end into the upstream location or the downstream location, respectively.

Other features and advantages of this invention will become more apparent in the following detailed description of the preferred embodiment of this invention, with reference to the accompanying drawings, in which:

FIG. 1 is an exploded view of a conventional ratcheting driver handle;

FIG. 2 is a cross sectional view of the conventional ratcheting driver handle, illustrating the internal configuration thereof;

FIG. 3 is an exploded view of the preferred embodiment of a ratcheting driver handle of this invention;

FIG. 4 is a schematic sectional view of the preferred embodiment;

FIG. 5 is a fragmentary sectional view of the preferred embodiment, illustrating idle rotation of the handle;

FIG. 6 is a fragmentary sectional view of the preferred embodiment, illustrating a state where the handle is rotated in the counterclockwise direction to perform a tightening operation on a workpiece;

FIG. 7 is a sectional view of the preferred embodiment, illustrating how a gear member is kept to mesh constantly with the pawl unit in order to perform the tightening operation; and

FIG. 8 is a modified preferred embodiment of this invention.

Referring to FIGS. 3 and 4, the preferred embodiment of a ratcheting driver handle for a driver bit according to this invention is shown to include an elongated body 10, a ratcheting mechanism, a spring member 50, a retaining member 13, first and second barrier members 111, 112, and a shank 71.

As illustrated, the elongated body 10 has an end portion 10A formed with an inner annular wall 11 that extends in an axial direction to define an axial hole. The axial hole opens at the end portion 10A.

The ratcheting mechanism is disposed in the axial hole, and includes a gear member 20 that is disposed to be rotatable and coaxial relative to the axial hole. The gear member 20 has a coupling end 21 adapted to engage the shank 71, and a rim portion disposed around the axial direction. The rim portion is provided with a tooth member 22 that is spaced apart from the annular wall 11 in a radial direction to define an annular chamber 15 therebetween. The ratcheting mechanism further includes a pawl member 30 disposed in the annular chamber 15, and having a fulcrum point lying in a fulcrum line 31 parallel to the axial direction, and first and second tooth portions 33, 32 disposed at two sides of the fulcrum line 31 opposing each other in such a manner that one of the tooth portions 33, 32 engages the tooth member 22 when the fulcrum point 31 is shifted between first and second positions along a line parallel to a chord line relative to the gear member 20.

The spring member 50 includes a mounting end 52 secured to the fulcrum point 31, and a free end 53 that extends angularly from the mounting end 52 around the gear member 20. The free end 53 of the spring member 50 is slidably retained in first and second anchored points 132, 131 that are disposed angularly on the inner annular wall 11 when the fulcrum point 31 is shifted between the first and second positions 52a, 52b, respectively.

The retaining member 13 is disposed on the inner annular wall 11 to slidably anchor the free end 53 at, in a clockwise direction, a downstream location which corresponds to the second anchored point 131 (see FIG. 5), and an upstream location which corresponds to the first anchored point 132 (see FIG. 6). The tooth member 22 is ratcheted by the second tooth portion 32 in a counterclockwise direction against a first biasing action of the spring member 50 generated when the free end 53 is at the second anchored point 131 and the mounting end 52 is at the second position 52b. The tooth member 22 is ratcheted by the first tooth portion 33 in the clockwise direction against a second biasing action generated when the free end 53 is at the first anchored point 132 and the mounting end 52 is at the first position 52a.

The first and second barrier members 111, 112 are disposed respectively to hinder the disengaged one of the first and second tooth portions 33, 32 from moving away from the tooth member 22 in the radial direction when one of the first and second tooth portions 33, 32 is brought to engage the tooth member 22 by shifting the fulcrum point 31 between the first and second positions 52a, 52b, thereby pulling or pushing the mounting end 52 so as to drag or to move over the free end 53 into the upstream location or the downstream location, respectively.

In the preferred embodiment, the elongated body 10 further includes an annular shoulder 141 disposed transversely on the inner annular wall 11 and inwardly of the end portion 10A so as to define a narrower inner annular wall 12 that extends in the axial direction for receiving rotatably the gear member 20 therein. The elongated body 10 further includes a pair of spaced partitions 14 formed on the annular shoulder 141 and extending toward the end portion 10A thereof to define in cooperation with the first and second barrier members 111, 112 a guideway 151 of a length greater than that of the pawl member 30 to permit shifting movement of the fulcrum point 31 between the first and second positions 52a, 52b. The pawl member 30 has an intermediate portion 311 formed between the first and second tooth portions 33, 32. The intermediate portion 311 extends along the axial direction, thereby serving as the fulcrum point 31. The elongated body 10 further includes an axially extending accommodating groove 16 formed in the inner annular wall 11 between the first and second barrier members 111, 112 and in communication with the end portion 10A to receive the mounting end 52 of the spring member 50 therein.

The preferred embodiment further includes a turnable disc 40 disposed transversely on the end portion 10A of the elongated body 10 and turnable around the axial direction so as to move the spring member 50 to shift the fulcrum point 31 in the guideway 151 between the first and second positions 52a, 52b. The turnable disc 40 has a central hole 41 adapted for passage of the shank 71, and two insert holes 44, 43 formed therethrough for passage of the mounting end 52 and the free end 53 of the spring member 50, respectively.

The preferred embodiment further includes a selector cap 60 disposed to be turnable around the axial direction and coupled to rotate the turnable disc 40. The selector cap 60 has a central hole 61 adapted for passage of the shank 71, and a plurality of angularly spaced plugs 62 disposed around the central hole 61. The turnable disc 40 further has a plurality of angularly spaced sockets 42 in alignment with the plugs 62 to receive the plugs 62 and transmit turning of the selector cap 60 to the turnable disc 40.

Referring to FIG. 7, note that the mounting end 52 is provided with an insert 520 (see FIG. 3) that projects inwardly and radially therefrom in order to facilitate insertion thereof in the intermediate portion 311 of the pawl member 30 such that the insert 520 swivels relative to the top portion 54 of the mounting end 52 so as to bring one of the first and second tooth portions 33, 32 to mesh constant with the tooth member 22 during idle rotation of the elongated body 10 so as to generate continuous clicking sounds.

The preferred embodiment further includes an outer housing 80 sleeved securely on the elongated body 10 to permit firm gripping thereof.

Because the pawl member 30 is swingeable about the insert 520 (serving as the fulcrum axis), little force is required to rotate the elongated body 10 to cause idle rotation thereof. When performing the tightening operation, the preferred embodiment provides an effective torque on the workpiece. Thus, the objects of this invention are achieved.

Referring to FIG. 8, a modified preferred embodiment of this invention is shown to similar to the previous embodiment in structure except in that the housing 80A is of an L-shaped while the shank 70A has an outer polygonal surface 72A. The features and objects are remained the same.

With this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated in the appended claims.