Technical Field

This invention relates to a one-way clutch, comprising two coaxial sleeves, one being driving and the other driven, and therebetween clutch means for torque transmission between the sleeves only in one of the two rotational directions of the driving sleeve- Background Art

A one-way clutch - or freewheel clutch, as it is sometimes referred to - can be regarded as an engineering element for performing the function of transmitting a rotational torque or movement between two shafts only in one direction. Such engineering elements are often mass produced and can be purchased from stock. They can be of different types within the general definition above, such as bails or rollers cooperating with inclined ramps in one of the sleeves, wedges or tilting bodies, or spring-loaded, hinged pawls.

For this engineering element the intended, reliable function, often under severe conditions, is of outmost importance, but in many cases the price for obtaining this function is decisive for the choice of element. The Invention

The object of this invention is to achieve a one-way clutch of the type defined above, which is simple, sturdy, reliable - even under severe con¬ ditions, such as in an environmental sense - but still is price competitive with any other corresponding engineering element on the market. This is according to the invention attained in that the clutch means in the one-way clutch comprises at least one tongue-shaped, inherently deflectable element, which is attached to one of the sleeves and is directed obliquely against the drive surface of the other sleeve.

In order to ensure a safe function and an even distribution of the forces, several tongue-shaped elements are preferably distributed substantially evenly around one of the sleeves.

An especially cost-effective and simple embodiment can be obtained in that the tongue-shaped elements are stamped-out at three sides of a metal band, preferably made of spring steel, in the longitudinal direction thereof, the band thereafter being attached to the periphery of one of the sleeves, so that the elements protrude substantially tangentially therefrom.

In order to ensure force-transmitting cooperation with the tongue- shaped elements the drive surface of the other sleeve is preferably provided with teeth or the like.

Brief Description of the Drawing

The invention will be described in further detail below reference being made to the accompanying drawing, in which Fig. 1 is a side view of a one¬ way clutch according to the invention, Fig. 2 is a side view of a band-shaped clutch means for the clutch according to Fig. 1, and Fig. 3 is a plan view to a larger scale of a part of the clutch means shown in Fig. 2. Detailed Description of a Preferred Embodiment

A one-way clutch shown in Fig. 1 comprises three coaxial parts, namely an inner sleeve 1, a clutch means 2, and an outer sleeve 3. If the inner sleeve 1 is the driving sleeve of the clutch, for example being mounted on a drive shaft (not shown), the outer sleeve 3 will be the driven sleeve only capable of being driven in one rotational direction as indicated by an arrow thereon, due to the design of the clutch means 2 to be described below.

The clutch means 2 is shown in Figs. 2 and 3 and is in the form of a metal band, for example made of spring steel, with a number of stamped-out, tongue-shaped elements *, preferably evenly spaced along the band. The band is cut to length and formed to a ring, as shown in Fig. 2, with a diameter corresponding to the outer diameter of the inner sleeve 1. Due to the elasticity of the band material, the elements Ψ will now protrude sub¬ stantially tangentially from the band. The ring thus created is to be firmly attached to the inner sleeve 1 in any appropriate way.

The outer sleeve 3 is then slipped ^" on, the dimensioning being such that the elements * hereby have to be slightly deflected, so that a certain pressure is excerted by them on the inner surface of the outer sleeve, called a drive surface 3'. This drive surface may preferably be provided with transverse teeth or the like so as to ensure a proper engagement with the tongue-shaped elements 4.

At a rotation of the inner sleeve 1 or driving sleeve in the clock-wise direction as shown in Fig. 1, the outer sleeve 3 or driven sleeve will also rotate due to the force transmitting engagement between the elements 4 and the drive surface 3'. At a rotation of the driving sleeve 1 in the opposite or counter-clockwise direction the elements will only deflect and slip on the drive surface 3' of the driven sleeve 3 unable to transmit any driving force, the result being that no rotation is imparted to the driven sleeve 3.

In the reasoning above the inner sleeve 1 has been regarded as driving; with the same effects as described the outer sleeve 3 can be driving and the inner sleeve 1 driven.

In the preferred embodiment the band 2 with the elements is attached to the inner sleeve 1, which is most advantageous, as in such a case the elements will protrude tangentially by the inherent elasticity of the band 2. However, it would of course be possible to provide the elements Ψ on the inner periphery of the outer sleeve 3. Also, the elements can be formed as integral parts of either sleeve 2 or 3, i.e. stamped out of the sleeve itself.

It is to be noted that the invention resides in the specific design of the clutch means 2- and that the design of the sleeves 1 and 3 can vary widely. Other modifications are possible within the scope of the appended claims.