Ratcheting tools are often required in engineering in general and the automotive and/or aircraft industries specifically. The ratcheting tools are typically used where it is necessary to connect components with screws. The ratcheting tool, also called a ratchet, consists of a lever arm and a tool head. The tool head comprises a drive housing in which a rotating part, typically a gear wheel is rotatably mounted. A connector for a plug-on or plug-in tool is connected to the drive. A locking pawl in the drive housing permits only one direction of rotation of the gear wheel. In this way, a torque is transmitted in one direction of rotation and in the other direction of rotation the lever arm can be return to a starting position. Thus, during operation the ratcheting tool should not be removed from the screw. With a switch, the locking pawl can lock the gear wheel in one direction of rotation as well as in the other direction of rotation. This allows setting a clockwise rotation or a counter-clockwise rotation for transmitting torque.
The Taiwanese Patent M434 653 discloses a ratcheting tool with a drive housing and a lever attached to it. In the drive housing, a gear wheel is rotatably mounted. On the gear wheel a square profile is provided as a plug for a plug-on tool. A switch selects between two spring-loaded locking pawls in the drive housing. The switch sets the locking pawls into suitable locking positions. Each of the locking pawls allows only one direction of rotation of the gear wheel. Hence, depending on the switch position of the switch either the clockwise rotation or the counter-clockwise rotation is set up. Different lock-in positions are provided for the switch. A housing cover closes the drive housing. Only the male square profile of the connector protrudes through an opening in the housing cover.
German Patent document DE 20 2012 102 520 U1 discloses a wrench with a ratchet. The wrench comprises a ratchet body, a drive mechanism, a cover ring and a regulating part. An opening is provided at one end of the ratchet body. A receiving space is formed axially in an inner wall of the opening and corresponding to the ratchet body, wherein the receiving space coincides with another end of the ratchet body. The wrench further includes a lateral indenting opening on one side of the receiving space. An insertion groove is formed axially in a bottom of the receiving space and according to the ratchet body. The regulating part is inserted into this insertion groove. Furthermore, a positioning groove is provided axially in a bottom of the insertion groove and corresponding to the ratchet body. The drive mechanism is made up of a ratchet and a drive element. The ratchet is inserted in the opening. Around an outer periphery of the ratchet a toothing is provided. The drive element is inserted in the receiving space wherein an abutment surface is formed at each of the two ends of the drive element. The two abutment surfaces rest on the bottom of the receiving space. On one side of the drive element two indenting toothings are provided which are arranged close to each other. The two indenting toothings are formed according to the ratchet, while the toothing of the ratchet is selectively indented in one of the two indenting toothings. The opening and the lateral indenting opening of the receiving space are covered by a covering ring. The covering ring is provided with an opening, wherein the opening is formed in accordance with the ratchet and retains a top side of the ratchet. The regulating part is composed of a switching element, a first elastomer and a second elastomer. The switching element is inserted into the insertion groove and can rotate therein. The switching element comprises two adjacent notches. The positioning groove is selectively formed in accordance with one of the two notches. The first elastomer is inserted in the positioning groove for selectively abut against one of the two notches of the switching element. The second elastomer is attached to the switching element, to abut against the drive element. When rotating the ratchet about the ratchet body in one direction, the toothing of the ratchet is indented in one indenting toothing of the drive element. During the rotation of the ratchet about the ratchet body in the other direction, the toothing of the ratchet is gradually disengaged from an indenting toothing of the drive element.
German Patent document DE 1 678 400 teaches a reversible ratchet. The reversible ratchet is adapted for transmitting torque exerted by a drive lever to a tool actuated by the ratchet, for example a socket wrench for tightening nuts, bolt heads, etc., wherein the ratchet comprises a head with a drive lever, a recess and a therein disposed ratchet wheel, which is toothed on its circumference and has a coupling shaft for mounting the tool. The ratchet comprises a drive lever, a ratchet wheel and a ratchet mechanism, the latter including a pawl by means of which the rotational force is transmitted from the drive lever to the driven ratchet. Many designs are characterized by a single, double-acting locking pawl which is moved between two different positions or oscillates back and forth about a centrally mounted pin. The shapes and arrangements of the various pawls are such that a high bending stress or shear stress is created in the locking pawl when a stress occurs by means of the drive lever. A switching lever comprises a bearing pin. The switching lever has a locking mechanism which can be clicked into two positions. For this purpose, the bearing pin comprises a blind bore into which a spring-loaded ball is inserted. The ball can engage in two notches and thus two positions.
German Patent document DE6808518 U relates to a lever wrench with a ratchet for two directions of rotation, consisting of a ratchet wheel carrying the driver fitting, the ratchet wheel carrying a toothing on its circumference, and a blocking member with a counter-toothing of the same radius which is pressed against the ratchet wheel by a spring. One end of the spring is arranged in a rotating body which can be rotated by means of a manually operable lever for selecting the direction of rotation.
European Patent document EP 1961521 B1 provides a ratcheting tool. The ratcheting tool includes a body and a gear wheel, which is disposed in the body and has a plurality of teeth which define a circumference of the gear wheel. The ratcheting tool comprises a locking pawl with a plurality of teeth pointing to the gear wheel, wherein the pawl is disposed in the body so that the locking pawl with respect to the gear wheel is laterally movable between a first position in which the pawl is arranged between the body and the gear wheel, so that the body transmits torque via the pawl in a first rotational direction, and a second position in which the pawl is arranged between the body and the gear wheel so that the body transmits torque via the pawl in an opposite direction of rotation. The document also discloses an externally operable change-over switch, with which the direction of rotation and the engagement of the toothing with the gear wheel for transmitting torque is set. The ratcheting tool includes a hinge connecting the pawl to the switch, wherein the switch is provided with a switching pin which is rotatably mounted in a body and has a projection, which engages in a recess of the locking pawl for switching. A blind hole with a spring is provided in the switching pin of the switch. A spring-loaded hinge pin is provided in the blind bore on the side facing the hinge, which passes through the projection of the switching pin into the recess of the pawl.
An essential drawback of the prior art is that that the switching mechanism for the ratchet drive is relatively complicated with many individual components. This makes the production of such tools expensive. With respect to the prior art ratchets it has been found that the switching mechanism switches uncontrollably by itself in a highly undesirable manner.
In view of the above, it has been long felt and unsolved need to provide a ratcheting tool which avoids the disadvantages of the prior art and to provide a switching mechanism for ratcheting tools constructed simply and inexpensively, wherein the switching mechanism is prevented from switching by itself during operation.
USPTO Backgrounds
USPTO Backgrounds