EP2732920B1 - Ratcheting mechanism - Google Patents

Description

Technical area

The invention relates to a ratchet tool with a tool head, according to the introductory part of claim 1.

State of the art

Such ratchets, also called ratchets, are used in mechanical and tool engineering, especially in assembly technology. For example, screws can be tightened and loosened with ratchets. The ratchets usually have a lever and a tool head. The tool head of the ratchet can accommodate a socket insert. If the tool head directly receives a screw, one speaks also of ratchet wrenches. By combining two Pawls, which transmit a pivoting movement of the lever in one direction only, is automatically locked during a movement in the opposite direction. Basically, there are also ratchets that are operated in addition to the purely mechanical versions, to facilitate work with compressed air or electric. If space is limited or if there is a high level of force, hydraulically driven ratchets are also used.

The ratchet or ratchet is a tool for generating a rotating rotary movement within a limited work space, usually for loosening or tightening screw. Usually, depending on the fineness of the teeth inside the ratchet a rotation angle of at least 10 to 15 degrees is required to achieve a rotation of a drive square. Special fine ratchets have such a fine toothing that already a rotation angle of about 5 degrees is sufficient, so that even under extremely tight conditions screws and nuts can be moved. "Free-wheeling catches" are doing without any screening.

The known ratchet mechanisms have a rotating part with radial external toothing. A blocking element with a radial toothing engages radially in this external toothing of the rotating part. The locking element allows the rotary member to rotate only in one direction. By a switching mechanism, it can be rotated in the other direction accordingly. In the respective blocking direction, the torque is transmitted from the ratchet to the workpiece, such as a screw, for tightening or for releasing.

From the DD 255241 A3 For example, a ratchet with a ratchet lever is known, in which a ratchet wheel is mounted, which is preferably connected to an additional, continuously acting drive. On the side of the ratchet lever are an upper and a lower stop. In the ratchet lever, a shift drum is rotatably mounted. In the shift drum are a first keyway, a second keyway and a third keyway, wherein also in the shift drum, a switching lever is used. The ratchet lever has a hydraulically actuated ball detent lock and a locking piece for a second locking mechanism.

These known ratchet tools have a radial external toothing. Also, the blocking element is arranged radially. As a result, the tool head requires a certain size to ensure the function of the ratchet mechanism. Disadvantage is therefore that the tool head is relatively large dimensions. This makes hard-to-reach fittings with such tools practically unattainable.

The US 5,388,479 discloses a ratchet tool with a tool head, the tool head having an insert coupled to a ratchet mechanism for transmitting torques. A socket or screw is inserted into the insert. The ratchet mechanism has a rotary part for transmitting torque, which has a first toothing on its first end face. In this toothing engages a first annular blocking element. For changing the direction of rotation, a second annular blocking element is used. The second locking element engages in one of the first toothing opposite and opposite, the second toothing of the rotary member. With a switching mechanism can be switched between the locking elements, so that the torque can be transmitted once in one direction of rotation and once in the other direction. In each case engages the one locking element in the rotary part and the other locking part is released.

The DE 299 16 751 shows a ratchet wrench with a rotating part, on whose one end face a sawtooth-shaped toothing is provided. To transmit a torque, a spring-loaded pawl engages in this toothing of the rotary part. To change the direction of rotation, the tool must be turned. It does not have a switching mechanism. This makes it necessary that the shaft is formed as straight as possible. The user does not necessarily come in all confined spaces with this tool and must also choose a different tool for many applications.

The US 2004/00891 06 A1 describes a ratchet tool with a rotating part. The rotating part also has a toothing on its front side. This gearing engages in a pawl for transmitting torque. To change the direction of rotation is also required that the tool is rotated.

The DE 25302 discloses a rotary part for a wrench with different teeth each for the right and left rotation. The pawl is formed here by a tooth-shaped wedge. By turning the web-shaped wedge, the direction of rotation can be set to transmit a torque. For larger torques, however, there is a risk that the tooth-shaped wedge bends or breaks, because the forces are not transmitted evenly to the rotating part. become.

Disclosure of the invention

The object of the invention is therefore to behaaffen a ratchet or a ratchet, which eliminates the disadvantages of the prior art. It is also a concern of the invention to provide a tool head for a ratcheting or ratchet tool with a small amount, in order to get to difficult to access fittings well. There are no losses in terms of functionality due to the smaller dimensions compared to conventional ratchet tools arise.

According to the invention this object is achieved in that in a ratchet or Ratsehenwerkzeug of the type mentioned the ratchet mechanism has a rotary part for transmitting torque, which has on its front side a toothing, in which engages a locking element, wherein the end face alternately a sawtooth-shaped toothing for a Right and left has a rotation, wherein the one blocking element of the switching mechanism lock one direction of rotation and another blocking element the other direction of rotation of the rotating part. The invention is based on the principle that the blocking element is no longer to be arranged radially relative to the rotating part. As a result, no radial external toothing is needed. Here, therefore, smaller diameter can be achieved in the rotary part. While in conventional ratchet tools the locking element and the toothing were in a radial plane, For example, the present ratchet mechanism is disposed on the end face of the rotary member. This allows a much more compact design can be achieved. The

Effect and function of the ratchet mechanism is thereby affected by this design in any way.

In an advantageous embodiment of the ratchet tool according to the invention, the blocking element is spring-loaded. In this case, the blocking element is pressed against the teeth on the front side due to the spring force. By turning the rotary part ratchets the locking element on the teeth. However, the ratchet mechanism is designed so that the rotating part can only rotate in one direction. When turning in the other direction, a torque is transmitted to the toothing of the rotating part via the blocking element. The spring force causes the blocking element to remain in contact with the toothing for transmitting power. The ratchet tool has a tooth, which engages in the frontal toothing of the rotating part. This measure serves to ensure that the blocking element can engage precisely in the toothing. In this case, several teeth can be provided simultaneously. The number of teeth depends in particular on the forces to be transmitted. The teeth are preferably designed so that they fit the contour of the toothing on the front side of the rotating part.

A further advantageous embodiment of the ratchet tool or ratchet tool according to the invention is achieved in that the toothing of the rotary member cooperates with the locking element due to their geometry such that only one direction of rotation is made possible. This measure causes only one direction of rotation for the rotating part of the ratchet mechanism is allowed. The other direction of rotation is locked and eventually used for power transmission.

A preferred embodiment of the ratchet tool according to the invention is further achieved by the ratchet mechanism arranged in a housing and / or a lever for power transmission is provided for the ratchet mechanism. The ratchet mechanism is thus protected against contamination. As a result, it is also possible to use extremely small gears, which are protected against dirt and other environmental influences. Due to the small toothing even very small angles can be used. Preferably, a lever transmits the force to the ratchet mechanism. A user then does not need so much force to manually tighten a screw, for example.

In the ratchet tool according to the invention a switching mechanism for changing the direction of rotation is provided. Through the switching mechanism, the ratchet and ratchet tool can be rotated in both directions for power transmission. By simply switching the direction of rotation or the reverse direction of the rotary part be determined. The tool can then be used for both tightening and loosening screws without having to turn it.

On one end side of the ratchet tool according to the invention a toothing for a right and a toothing for a left-hand rotation is alternately provided. In this way, a switching mechanism can be realized with simple measures. The blocking elements or the teeth must be designed accordingly for this purpose in terms of their geometry. It must lock a blocking element in one direction of rotation and another blocking element in the other direction of rotation of the rotating part. These locking elements are then activated depending on the position of the switching mechanism. This allows the ratchet to turn either in one direction or in the other direction.

In an alternative to the aforementioned switching mechanism, the toothing may also be provided on both end faces of the rotary part. Preferably, therefore, an end face of the rotary member is provided with a toothing for a clockwise rotation in the ratchet tool or ratchet tool according to the invention. On the other end face of the rotating part a toothing for a counterclockwise rotation is provided accordingly. In this case, the respective blocking element must be designed in a suitable manner. Depending on which side is activated by means of the switching mechanism, the direction of rotation can be determined. This measure also makes it possible to make the teeth small for each direction of rotation. This makes it possible to achieve very low angles of rotation when tightening or loosening screws.

In one, variant of the ratchet tool or ratchet the locking element is annularly formed with a toothing, wherein the toothing of the locking element engages in the frontal toothing of the rotary member for torque transmission. The advantage of this variant is that the largest possible area for the transmission of torque is provided. The forces in the torque transmission are distributed over all the teeth of the toothing, whereby a lower load of the individual teeth takes place. Even when breaking a single tooth, the torque can be without large Transmit impairment. As a result, injuries to the user can be avoided.

Further advantages and embodiments of the invention will become apparent from the subject of the dependent claims, as well as the drawings with the accompanying descriptions. Exemplary embodiments are explained in more detail below with reference to the accompanying drawings.

Short description of the drawing

Fig. 1

schematically shows the tool head of a ratchet tool according to the invention from the side in section.

Fig. 2

schematically shows the tool head of a ratchet tool according to the invention in a three-dimensional view in section.

Fig. 3

shows a schematic diagram of a section of the rotary part with its toothing, in which engages a spring-loaded locking element.

Fig. 4

shows a detail in a schematic diagram of a tool head with a rotating part with teeth and an annular blocking element.

Preferred embodiment

In Fig. 1 at 10 a ratchet tool according to the invention is called. The ratchet or ratcheting tool 10 is hereinafter called only ratchet tool. In the FIG. 1 a cutaway tool head 12 of the ratchet tool 10 can be seen from the side. The tool head 12 has a substantially cylindrical head housing 14. On the head housing 14, the approach of a lever 16 is attached. The lever 16 usually has an ergonomic handle for easier operation, which is not shown here.

In the head housing 14 of the tool head 12, a ratchet mechanism 13 is provided with a rotary member 18. The rotary member 18 is rotatably supported in the head housing 14. The rotary member 18 has end faces 20, 22. On the front side 20 is a toothing 24. The toothing 24 is formed like a sawtooth, i. the geometry of the profile of the toothing 24 has a vertical 26 and an oblique edge 28. The ratchet mechanism 13 further includes spring-loaded locking elements 30. The locking elements 30 are tooth-shaped. The spring-loaded locking elements 30 engage in the toothing 24 of the rotary member 18. Cover 32 of the head housing 14 is slightly stronger. As a result, holes 34 may be provided, in which the locking elements 30 are arranged. In the holes 34 30 coil springs 36 are also provided for the spring load of the locking elements.

The blocking elements 30 are designed such that they fit into the contour of the toothing 24. Thus, a substantially vertical surface 38 of the locking element 30 comes into contact with the vertical edge 26 of the toothing 24. Vertical here means: substantially parallel to the axis of rotation 39 of the rotary member 18. On the other hand, a likewise inclined surface 40 of the locking element 30 with the oblique edge 28 of the toothing 24 of the rotary member 18 fits. In this way, the rotary member 18 can only rotate in one direction of rotation, namely only on the inclined edges 28. The other direction of rotation is provided for transmitting a torque for the ratchet tool 10. Here meet the vertical edges 26 and surfaces 38 to each other and lock the corresponding direction of rotation. The blocking elements 30 are arranged stationary relative to the head housing 14, while the rotating part 18 can rotate in the head housing 14 at least in one direction.

Fig. 2 shows the tool head 12 accordingly Fig. 1 in a three-dimensional view. Also the view of Fig. 2 is shown cut. If the same components are described as in Fig. 1 , corresponding reference numerals are also chosen. The rotary member 18 is rotatably supported in the head housing 14. The rotary member 18 is hollow inside. This gives the rotary member 18 inner surfaces 42. The inner surfaces form a star-shaped inner profile 44, in which suitable plug-in inserts or screws can be used. The sockets or screws are not shown here. The sawtooth-shaped toothing 24 in profile is arranged on the end face 20 of the rotary part 18. In the toothing 24, the spring-loaded locking elements 30 engage.

Out FIG. 3 the operation of the ratchet tool 10 becomes clearer. In FIG. 3 Namely, a section of the rotary member 18 is shown. On the front side 20 of the rotary member 18 is a partial view of the sawtooth toothing 24. The locking element 30 is spring-loaded with the coil spring 36 in the bore 34 of the cover 32 is provided. The contour of the blocking element 30 is cylindrical, wherein the cylinder is cut obliquely in the lower region. As a result, the contour of the blocking element 30 can adapt to the profile of the sawtooth-shaped toothing 24. In this enlarged detail view of the FIG. 3 it is clear that the rotary member 18 can move freely only to the left. The toothing 24 pushes namely through the inclined surface 40 of the locking element 30 against the spring force of the coil spring 36 therethrough. The rotation to the right, however, is prevented by the blocking element 30. The vertical surfaces 38 of the locking member 30 prevent with the vertical edge 26 of the toothing 24 a clockwise rotation of the rotary member 18. As a result, a torque on the head housing 14, which is connected to the lever 16, be placed on the rotary member 18. The rotary member 18 transmits the torque by means of a socket wrench, not shown here turn on a workpiece, such as a screw.

In Fig. 4 In a cutout, a tool head 46 is shown as an exploded view. In the tool head 46, the torque is transmitted to the rotary member 18 with an annular locking member 48. The locking element 48 is to rotatably within a housing 49 of the tool head 46. Teeth 50 of the locking element 48 form a sawtooth toothing 52, which engages in the toothing 24 on the end face 20 of the rotary member 18. The annular locking element 48 is biased by a coil spring 51. The toothing 24 of the rotary member 18 is also formed like a sawtooth. By turning the tool head 46 in a first direction, a torque is transmitted. Turning the tool head in the other direction causes no torque to be transmitted. During the transmission of the torque, the force applied in each case over the mutually perpendicular surfaces 54, 56 of the saw-shaped teeth 24, 52nd transfer. In the other direction of rotation slide the inclined surfaces 58, 60 against the spring force of the coil spring 51 over each other. When turning the tool head thus no torque is transmitted to a workpiece.

Claims (5)

1. A ratchet or ratcheting tool (10) with a tool head (12), wherein the tool head (12) comprises a top part or insert, which is coupled with a ratchet mechanism (13) for transmitting torque and wherein a wrench socket or wrench insert or a screw is attached on the top part or in the insert, the ratchet mechanism (13) comprises a rotary member (18) for torque transmission, which comprises a toothing at its front side (20), in which a locking clement (30) engages, a switching mechanism is provided for changing the rotational direction and the locking element (30) is formed having a tooth-shaped toothing (52), wherein the toothing (52) engages into the toothing (24) on the front side of the rotary part (is) for transmission of torque,
   characterized in that
   the front side (20) alternately comprises a sawtooth-shaped toothing (24) for a right and a left turn, wherein one locking element (30) of the switching mechanism locks one direction of rotation and another locking element locks the other direction of rotation of the rotating part.
2. A ratchet or ratcheting tool (10) according to claim 1, characterized in that the locking element (30) is spring-loaded.
3. A ratchet or ratcheting tool (10) according to any one of claims 1 or 2, characterized in that the toothing (24) of the rotary part (18) interacts with the locking element (30) due to their geometry such that only one direction of rotation is made possible.
4. A ratchet or ratcheting tool (10) according to any one of claims 1 to 3, characterized in that the ratchet mechanism (13) is arranged in a casing (14) and / or a lever (16) is provided for transmitting power for the ratchet mechanism (13).
5. A ratchet or ratcheting tool (10) according to claim 4, characerized in that the front sides (20, 22) of the rotary member each comprise a toothing (24) for a right and a left turn, wherein a suitable locking element (30) is provided for each toothing (24).

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