Torque wrench which can be used as a ratchet

1 . A screw driving tool comprising:

a switchover element, a blocking element, a ram, a torque transmission element, a torque transmission section, a torque output element, a spring, an adjustment device, and a housing;

wherein the switchover element is movable from a release position into a blocking position:

wherein the ram acting on the torque transmission element is movably located in the housing and is biased by the spring;

wherein a pretension of the spring is adjustable by the adjustment device in order to adjust a torque limit;

wherein the switchover element cooperates with the blocking element, the blocking element being movable from a first position to a second position;

in the release position, the blocking element being in the first position and allowing movement of the ram, wherein the tool has a function of a torque wrench, transferring only torques which lie below the torque limit from the torque transmission element to the torque transmission section coupled to the torque output element;

in the blocking position, the blocking element being in the second position and inhibiting movement of the ram, wherein the tool has a function of a standard screw driving tool, with which torques can also be transferred from the torque transmission element to the torque transmission section which lie above the torque limit;

wherein the torque limit can be adjusted by the adjustment device.

2 . The screw driving tool according to claim 1 , wherein the torque output element which defines an axis is mounted in the housing; and

the torque transmission element, is pretensioned by a force of a force accumulator which can be adjusted by the adjustment device.

3 . The screw driving tool according to claim 2 , wherein the torque transmission element engages in a depression of the torque transmission section, for coupling the torque transmission section to the housing so as to transmit the torques;

said torque-transmitting coupling being released when the torque transmission element leaves the depression in an edge-controlled manner against the force of the force accumulator, when the torque limit is exceeded;

the switchover element, in the release position permits the torque transmission element to leave the depression, but in the blocking position blocks the torque transmission element leaving the depression.

4 . The screw driving tool according to claim 3 , wherein the depression is a trough, a wall of which extends in cross-section to the axis along a circular arc line.

5 . The screw driving tool according to claim 4 , wherein a radius of the trough corresponds to a radius of the torque transmission element constituted as a cylinder, wherein an arc length of the radius of the trough is smaller than a quarter circle, wherein sections of the wall of the depression form inclined edges, so as to guide the torque transmission element out of the depression.

6 . The screw driving tool according to claim 2 , wherein the switchover element is a sleeve part guided displaceably on the housing and cooperates with the blocking element.

7 . The screw driving tool according to claim 6 , wherein the blocking element is mounted movably in a window of the housing.

8 . The screw driving tool according to claim 6 , wherein the blocking element is captured in the blocking position in a blocking recess of the ram, which is arranged in a force transmission path between the torque transmission element and the force accumulator.

9 . The screw driving tool according to claim 8 , further comprising two, three, four or more blocking elements,

wherein the ram comprises two, three, four or more blocking recesses each configured to receive one of the two, three, four or more blocking elements, and

wherein the two, three, four or more blocking recesses are arranged on a peripheral area of the ram.

10 . The screw driving tool according to claim 8 , wherein the torque output element is arranged in a head formed by the housing, wherein a drive arm projects from the head, in which the spring forming the force accumulator is arranged, which with an interposition of the ram acts on the torque transmission element.

11 . The screw driving tool according to claim 10 , wherein the switchover element is linearly displaceable relative to a direction of extension of the drive arm between the blocking position and the release position.

12 . The screw driving tool according to claim 6 , wherein the switchover element forms with a first section of its inner wall a bypass space for the blocking element in the release position and forms with a second section of its inner wall an abutment edge for the blocking element in the blocking position.

13 . The screw driving tool according to claim 1 , wherein a freewheel gear is provided in a torque transmission path between the torque output element and the torque transmission section.