Background of the Invention The present invention relates to a ratchet handle, comprising an elongated operating handle with a grip at one end and a tool holder at the opposite end and a reversible drive mechanism acting between the operating handle and the tool holder, which has a housing securely joined to the operating handle, which is made with a chamber delimited by an interior circular wall, a rotor jointed to the tool holder and housed in the chamber, said rotor being made with ramps defining, together with the circular wall, an even number of peripherally tapered spaces, housing rolling bodies and spring elements cooperating with said rolling bodies, a shift element rotatably mounted concentrically with the rotor and having fingers extending into the chamber.

Ratchet handles are usually used together with certain socket wrenches for hex nuts and hex head screws, the selected socket being snapped onto a tool holder in the form of a male element of polygonal cross-section. It is possible here to distinguish two main types of ratchet handles, one type having a drive mechanism with some form of toothed rachet wheel and pawls engaged therewith, while the other type uses a drive mechanism in the form of a stepless, reversible one-way clutch provided with clamping elements.

The latter type to which the present invention relates, has the advantage over the former that it can be used in confined spaces, which do not permit the rotation of the ratchet handle required in the former type for the pawl to snap over a ratchet tooth into engagement again.

A number of different solutions are available to the problem of providing a ratchet handle with stepless advancement which most are so complicated that they have not come into use in practice. US-A-4,457,416 describes, for example, a ratchet handle of the type described by way of introduction, which has been designed to be manufactured at a low cost by consisting of a few simple and inexpensive components permitting simple assembly. It drive mechanism has a hexagonal motor, which together with a surrounding cylindrical wall, dehmits six peripherally tapered spaces, which are separated two-by-two by three intermediate walls integral with the rotor. In each space there is a rolling body and a folded leaf spring. Between adjacent rolling bodies, the fingers of the shift element extend and by direct contact with one or the other adjacent rolling body upon rotation of the shift element between its end positions, it prevents the rolling body in contact therewith from exerting a clamping effect. However, this drive mechanism is, despite its intentions, relatively complicated on the one hand due to the large number of components and, on the other hand, by the complex shape of the rotor, which makes it expensive to manufacture.

Summary of the Invention The purpose of the present invention is to achieve a ratchet handle of the type described by way of introduction, which has a drive mechanism consisting of fewer components of simpler shape than the drive mechanism described above according to US-A-4,457,416 and which therefore can be manufactured at lower cost retaining the gap-free function.

This is achieved according to the invention by virtue of the fact that the fingers extend into the spaces between the spaces housing said rolling bodies, that each finger is peripherally fixed to one of said spring elements

abutting against the rolling bodies on either side of the finger, and that means- are arranged to keep each finger in one of two positions on either side of a symmetry position in its associated space to thereby bias via the springs the rolling bodies towards one end of each tapering space.

The design according to the invention can reduce the number of rolling bodies and loose spring elements by one half compared to the known described ratchet handle. Furthermore, the need for intermediate walls on the rotors is e minated, which means that it can be manufactured at substantially lower cost than the known described rotor.

Brief Description of the Drawings

Figure 1 shows an exploded view of one embodiment of a ratchet handle according to the invention.

Figure 2 shows a plan view of the left-hand end of the ratchet handle of Figure 1 with the operating element removed.

Description of the Preferred Embodiment

Figure 1 generally designates an elongated operating handle with a grip 2 at one end and a cylindrical housing 3 at its opposite end, which is made in one piece with the handle 1. The housing 3 has a cylindrical interior wall 4, which delimits an upwardly and downwardly open chamber 5. In the chamber 5 there extends a rotor in the form of a head 6 with hexagonal cross-section which is made in one piece with a male element 7 of square cross-section. The male element 7 serves as a tool or socket holder and has an outwardly spring biased locking ball 8.

The outer surfaces 9 of the head 6 define together with cylindrical interior walls 4 of the chamber 5 six peripheral spaces 10, each tapered in both peripheral directions. A rolling body in the form of a cylinder 11 is loosely housed in every other space 10. In the spaces 10 therebetween fingers 12 extend, which are uniformly spaced and fixed on a circular plate 13, which forms the shift knob for selection of the direction of rotation of the tool holder element 7, as will be described in more detail below. Three folded leaf springs 14 are placed in the spaces 10 between the cylinders 11 and abut with their respective end portions against the cylinders 11. Each spring 14 is shaped centrally to be fixed peripherally relative to a finger 12.

In the example shown in Figure 1, the center portion of each spring 14 has upper and lower arcuate, radially outwardly and inwardly directed portions 14a, 14b which between them grip each finger and thus fix the center portion of the spring 14 relative to the finger 12. The spring portions on either side of the center are in this example creased in V-shape.

In Figure 2, an example is shown in which the springs 14 are wave-shaped or U-shaped uniformly over the entire length. In the central trough 14, the respective finger 12 is inserted, and the shape of the trough is so adapted to the cross-section of the finger that a peripherally gap-free connection is obtained between the finger and the spring.

In those spaces 10 in which the fingers 12 are inserted, the rotor has a radially outwardly spring-biased locking ball 15, housed in a bore rotated midway between the two ends of the space 10. This means that the finger 12 can never center the spring 14 and the cylinders 11 on either side of the spring will never be centered in their respective spaces. Upon rotation of

the shift knob 13, the fingers 12 will always snap over from one side to the other side of the respective locking ball 15 and place the cyUnders 11 so close to one or the other end of the respective space 10 that the cylinder will be in contact with both the inner wall 4 of the chamber 5 and the opposite wall 9 on the rotor. Rotation of the housing 3 will cause the cylinders 11 in the known manner to be carried towards the adjacent end of the space 10 and be clamped securely between the wall 4 and the surface 9 of the rotor, so that the housing 3 and the rotor will be locked together as a unit, and the tool holder 7 will follow the rotational movement of the handle. Figure 2 shows the components in the position for tightening a screw.

In the embodiment shown, the operating knob 13 is screwed securely to the rotor 6 by means of a screw 16, so that the knob 13 is axially fixed but rotatable relative to the rotor 6. The knob 13 has a fluted edge 17 extending a short distance (less than a --t-illimeter) outside the edge of the housing 3, so that it can be easily gripped and rotated with the fingers and not only be turned a short distance for changing between tightening and loosening. Another substantial advantage of the drive mechanism according to the invention is that it is possible by means of the knob 13 and its fingers 12, the springs 14 and the cylinders 11 to rotate the rotor freely relative to the housing 3, which substantially facilitates, for example, tightening of the screw. Initially, when the screwing-in is easy, one does not need to pump the handle 1; rather, the screw can be simply screwed in by rotating the operating knob 13 until it becomes difficult, whereafter it is tightened finally by rotating the handle.