192 clutches and power-stop control – Clutches – Automatic
Reexamination Certificate
1999-12-20
2001-03-27
Marmor, Charles A (Department: 3681)
192 clutches and power-stop control
Clutches
Automatic
C192S046000, C081S063100
Reexamination Certificate
active
06206160
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a ratchet transmission control mechanism for a ratcheting tool for driving fasteners.
2. Description of the Related Art
U.S. Pat. No. 5,573,093 to Lee issued on Nov. 12, 1996 discloses a ratchet transmission control mechanism of a screwdriver that includes a casing having a head at one end, toothed shaft inserted into an axial center hole on the head to hold a bit for turning screw, two stop blocks mounted in a respective slot on the head of the casing and retained in place by a clamp for engagement with the toothed portion o the toothed shaft, an adjusting cap mounted around the toothed shaft over the head of the casing and retained in place by a locating ring. When the adjusting cap is turned to the middle position, the two stop blocks are forced into engagement with the toothed portion of the shaft for permitting the shaft to be turned by the casing in both ways. When the adjusting cap is turned to the leftward position or the rightward position, only one stop block is forced into engagement with the toothed portion of the shaft, and the shaft can be turned by the casing in one direction.
It is, however, found that assembly procedure of such a ratchet transmission control mechanism is troublesome and time-consuming. In addition, each of the stop blocks is engaged with the toothed portion of the shaft by one tooth and thus has poor ratcheting effect.
The present invention is intended to provide an improved ratchet transmission control mechanism for a ratcheting tool that mitigates and/or obviate the above problems.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide an improved ratchet transmission control mechanism for a ratcheting tool that can be assembled easily and quickly to thereby lower the assembly cost.
It is another object of the present invention to provide an improved ratchet transmission control mechanism for a ratcheting tool that provides reliable ratcheting effect by providing pawls having more teeth for engaging with the toothed portion of the spindle of the ratcheting tool.
In accordance with the present invention, a ratchet transmission control mechanism for a ratcheting tool with a handle comprises:
a cylindrical main body from which the handle of the ratcheting tool extends, the cylindrical main body including a longitudinal hole and a first transverse hole and a second transverse hole that are communicated with the longitudinal hole, the main body further including a groove, two first transverse receptacles, and two second transverse receptacles in an outer periphery thereof;
a pair of parallel first arcuate channels defined in the outer periphery of the main body and each including a first end that terminates in an associated said first transverse receptacle and a second end that is communicated with the groove of the main body;
a pair of parallel second arcuate channels defined in the outer periphery of the main body and each including a first end that terminates in an associated said second transverse receptacle and a second end that is communicated with the groove of the main body;
a spindle rotatably received in the longitudinal hole of the main body and including an end extended beyond the main body for driving a fastener, the spindle including a toothed portion disposed in the longitudinal hole of the main body;
a substantially U-shape first elastic member including two limbs and a connecting section interconnecting between the limbs, each said limb of the first elastic member having a distal end, the limbs of the first elastic member being mounted in the first channels with the distal ends of the first elastic member securely, respectively retained in the first transverse receptacles and with the connecting section of the first elastic member extended into the groove;
a substantially U-shape second elastic member including two limbs and a connecting section interconnecting between the limbs, each said limb of the second elastic member having a distal end, the limbs of the second elastic member being mounted in the second channels with the distal ends of the second elastic member securely, respectively retained in the second transverse receptacles and with the connecting section of the second elastic member extended into the groove;
a first pawl mounted in the first transverse hole of the main body, the limbs of the first elastic member being extended through the first pawl such that the first pawl is biased radially inward by the first elastic member to engage with the toothed portion of the spindle and that the first pawl is biased radially outward by the first elastic member when the connecting section of the first arcuate elastic member is pressed toward the distal ends of the first elastic member;
a second pawl mounted in the second transverse hole of the main body, the limbs of the second elastic member being extended through the second pawl such that the second pawl is biased radially inward by the second elastic member to engage with the toothed portion of the spindle and that the second pawl is biased radially outward by the second elastic member when the connecting section of the second arcuate elastic member is pressed toward the distal ends of the second elastic member;
a hollow switch cap mounted around the main body, the switch cap including an operative member projected from an inner periphery and movable among three positions upon turning the switch cap, wherein when the operative member is in a first of the three positions, the operative member presses against the connecting section of the first elastic member such that the first pawl is disengaged from the toothed portion of the spindle while the second pawl is engaged with the toothed portion of the spindle, thereby allowing the spindle to drive a fastener along a first direction, when the operative member is in a third of the three positions, the operative member presses against the connecting section of the second elastic member such that the second pawl is disengaged from the toothed portion of the spindle while the first pawl is engaged with the toothed portion of the spindle, thereby allowing the spindle to drive the fastener along a second direction opposite to the first direction, when the operative member is in a second of the three positions, neither the connecting section of the first elastic member nor the connecting section of the second elastic member is pressed by the operative member such that the first pawl and the second pawl are both engaged with the toothed portion of the spindle, thereby allowing the spindle to drive the fastener along either the first direction or the second direction; and
means for retaining the switch cap in the three positions and allowing the operative member of the switch cap to be moved to one of the three positions upon rotation of the switch cap.
In a preferred embodiment of the invention, the means for retaining the switch cap includes a transverse blind hole defined in the outer periphery of the main body. The switch cap includes three retaining depressions in the inner periphery thereof. A spring is received in the transverse blind hole, and a ball is received in the transverse blind hole and biased radially outward by the spring to be selectively retained in one of the three retaining depressions.
The outer periphery of the main body includes a guiding groove, and the switch cap includes a pinhole that is communicated with the guiding groove of the main body. A pin is extended through the pinhole. The pin has an end slidably guided in the guiding groove of the main body, thereby securely mounting the switch cap to the main body yet allowing the switch cap to rotate about the main body.
The inner periphery of the switch cap includes a first cavity for receiving a portion of the limbs of the first elastic member that is moved radially outward when the connecting section of the first elastic member is pressed by the operative member of the switch cap. The inner periphery of the switch cap further includes a secon
Alan Kamrath Rider Bennett Egan & Arundel, LLP.
Marmor Charles A
Rodriguez Saul
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