FR2477457A1 - Adjustable spanner with slidable cantilever jaw - has jaw threaded on cranked neck lever via rectangular window and is locked by wedging - Google Patents

Abstract

The adjustable spanner uses parallel fixed (1c) and movable (4) jaws which cantilever from the cranked neck (1b) of a hand lever (1a). Jaw is moved by sliding along the neck, being locked in the required position by an automatic wedging effect. The neck has a uniform rectangular cross-section, traversing a nominally oversize jaw (4) opening (0) of a similar configuration. The opening is slightly inclined relative to the active and trailing jaw faces. A spring loaded ball (9) may tilt the jaws to promote wedging, and a screw jack in the diagonally opposite position (5a) may augment the effect. Thumb pressure on either heel zones (5c,5b) may tilt the jaw into the slidable position.

Description

 The invention relates to a movable jaw tightening wrench with locking in position of the movable jaw by wedging.

 The object of the invention relates to the technical sector of hand tools.

We know well in this field the wrenches whose jaw housing does not remain fixed from one tightening to another.

 Furthermore, in this type of key, the movable jaw has a certain clearance with respect to the fixed jaw which produces an imprecise spacing between the two jaws.

 Systems for locking the movable jaw in the adjustment position have been proposed for adjustable wrenches, but they are complex and expensive.

 Another drawback results from the volume of the fixed jaw serving as a guide for the movable jaw; this volume makes it difficult to access such keys in tight spaces.

 Self-tightening keys are also known in this sector, the angle between the plane of the jaws and the axis of the handle is not constant, which poses with some a large volume of the head, a problem of tightening in cramped places.

According to the invention, it was desired to produce a movable jaw key, the manufacture of which is simple and economical, and the movable jaw of which can maintain a chosen position without play, with a minimum size of the jaws and a fixed angle between the faces of the jaws. and the handle.

The tightening key according to the invention is remarkable in that the movable jaw is not moved by any movable member: it is the thumb of the user which brings it into its clamping position.

 According to another characteristic, the movable jaw is held in position by wedging with respect to a guide on which it moves. Tightening a nut favoring this jamming.

According to another characteristic, at rest, the posit'oss of the movable jaw is maintained by a spring which promotes the wedging effect.

 These and other characteristics will become apparent from the description which follows.

 To fix the subject of the invention without however limiting it in the appended drawing.

 Figure 1 is a front view of the key with a section of the movable jaw in the position of maximum separation.

Figure 2 is a front view of the movable jaw alone.

Figure 3 is a view along F of the movable jaw alone
Figure 4 is a front view of the latch alone.

Figure 5 is a view along F of the latch alone.

Figure 6 is a section along AA of the assembly: latch plus movable jaw.

Figure 7 is a partial sectional view of the movable jaw on the guide, of a variant comprising the addition of a locking screw
In order to make the object of the invention more concrete, we now describe it in the nonlimiting embodiments illustrated in the figures of the drawing.

 As shown in Figure 1, the key has a handle (la) extended by a guide (lb) which is secured to a fixed jaw (lc).

 On the guide (lb), is positioned a movable jaw (4) locked by the latch (5) whose curved face is knurled.

 The latch is secured to the base of the movable jaw by three screws (6a, 6b, 6c) as shown in Figure 6.

 The movable jaw can as we see in Figure 1, move freely by sliding on either side of the guide (lb).

 I1 must at some point be able to stop the sliding of the movable jaw along the guide, it is here that the phenomenon of jamming appears, to do this, the face (4a) of the movable jaw and the face (5a) of the latch form a small angle (about 20) relative to the axis BB 'of the movable jaw.

 Furthermore, in a threaded hole (4b) of the movable jaw, a screw (7) compresses a spring (8) which pushes a ball (9) which, by pressing on the front face of the guide (lb), tends wedging the movable jaw assembly (4) plus latch (5) on the guide (lb).

 We realize that by tightening or loosening a nut with the key, we tend to accentuate the action of the spring (8), therefore increasing the jamming of the movable jaw which remains in position on the guide (lb).

To vary the spacing between the jaws, simply press with your thumb on the knurled part of the latch (5) which counteracts the pressure of the spring (8) and allows the movable jaw to slide along the guide ( lb). We see that to tighten the jaws, you must press on the part (5b) of the latch and to move them apart, you must press on the part (5c).

 I1 is possible to envisage that the movable jaw (4) and its latch (5) make only one piece, but, it is then necessary to provide its access to the assembly on the guide (lb), either by putting a straight handle , either by providing an added handle after mounting the movable jaw.

 The front face of the guide (lb) can be streaked to prevent the movable jaw from slipping when tightening or loosening.

 In an alternative embodiment illustrated in FIG. 7, the jamming effect at rest can be accentuated by the pressure of the screw (10) passing through the latch (5) and pressing on the rear face of the guide (lb ).

 The use of this key is very simple: the handle (la) being held firmly in hand, the thumb is placed on the knurled part of the latch (5), the jaws are moved aside then the key is placed on the nut, the thumb tightens by pushing on (5b) the movable jaw against the corresponding face of the nut, it is then enough to let go and tighten or loosen the nut.

 This key can advantageously replace a set of several simple keys, it can also replace the other keys with less easy handling.

Claims (4)

1 - Tightening wrench with movable jaw with locking in position of the movable jaw by wedging, comprising a body forming an operating lever (la), fixed jaw (lc) and having a guide (lb) on which a movable jaw ( 4) held on the guide by a latch (5); the key is characterized in that the movable jaw is held in position relative to the fixed jaw by wedging the two parallel faces (4a and 5a) on the guide (Ib). 2 - Wrench according to claim 1 characterized in that the jamming of the movable jaw (4) on the guide (lb) is favored at rest by a screw (7) compressing a spring (8) pushing a ball (9) which rests on the front face of the guide (lb) 3 - Tightening wrench according to claims 1 and 2 characterized in that the tightening or loosening of a nut promotes the jamming of the movable jaw (4) on the guide (lb).  4 - Tightening key according to claims 1 and 2 characterized in that the displacement of the movable jaw (4) along the guide (lb) is obtained by pressing the thumb of the user on the parts (5b) or ( 5c) of the latch (5) according to whether he wants to approach or move aside the jaws.