EP1060841A1 - Self-adjusting pliers - Google Patents

Abstract

The pliers comprise two branches joined by a rod (15) having a female collar (1) which pivots on a pin (A) and guides a male collar (2) which slides inside and pivots on the male branch by means of a pin (B). A spring (3) sets the collars and a second spring (5) unites one (1) of the collars with the female branch. The male branch (6) has a head (7) having an upper toothed jaw (10) and a window (8) with teeth (9). The female branch (11) with a large opening allowing the passage of the male head carries a lower toothed jaw (13) and a toothed lug (14) which pivots on a spindle (21).

Description

Pliers which consist of two jaw branches toothed and able to slide between them by means of a lug element which encased and slides in a longitudinal window in one of the toothed jaws are well known.

In search of a better adaptation of the jaws to the part to take pincers and maximum adhesion to it, pliers where the branches are joined later by a connecting rod which, under the pressure of at least one, from its ends, slides on one of the branches and allows the axis of the element to lug to move, was developed by U.S. Patents 4,651,598, 4,662,252, 4,922,770 and 5,020,399.

The sliding of the end of the rod obliges to have on the branch (es), grooves, channels, slides, orifices, to ensure that sliding and fitting the corresponding actuating springs on the connecting rod.

The need to have these grooves on the branches encourages, in order to facilitate manufacturing, to make branches based on plates of superimposed steel, of the sandwich type, but this solution gives a clamp having little mechanical resistance and poor durability. The second stage consisted to make the wrought iron branches, but keeping the grooves / holes poses machining and cost problems.

We also note that the travel of the ends of the branches, until the jaws exert real pressure on the workpiece pincers, was excessive.

Solicitor solved all of the above issues by giving a simple and surprising answer: the clamp will be made of wrought iron, but the connecting rod will not slide, which automatically resolves the reported drawbacks.

a).- Deux frettes qui se déplacent l'une par rapport à l'autre de façon télescopique, l'une d'entre elles pivotant sur la branche mâle et l'autre sur la branche femelle.

b).- Un premier ressort d'enchâssement des deux frettes;

c).- Un second ressort qui joint l'une des frettes à l'une des branches.

More specifically, the invention presents a clamp where the connecting rod consists of:

a) .- Two frets which move relative to each other telescopically, one of them pivoting on the male branch and the other on the female branch.

b) .- A first spring for embedding the two frets;

c) .- A second spring which joins one of the frets to one of the branches.

To better understand the object of the present invention, we represents, on the plans, a preferential form of practical realization susceptible of accessory changes which do not alter the basis.

Figure 1 is a partial sectional view of an embodiment practice of the clamp which is the subject of the invention, the jaws being open.

Figure 2 is a partial sectional view of an embodiment practice of the clamp of Figure 1, the jaws being closed.

FIG. 3 is a partial view of section A: A of FIG. 2.

A practical example is described below, not limiting, of the present invention.

The clamp consists, as everyone knows, of a male branch (6) having a head (7) with the upper toothed jaw (10) where a window (8) with teeth (9) and a female branch (11) with large opening (12), which allows the passage of the head (7) of the male branch (6) and carrier of the jaw toothed (13) lower and a lug element (14) toothed which pivots on an axis (21) and is fitted with the teeth (9) of the window (8).

Being the essential object of the invention, the provision is such that the male branch (6) and female branch (11) remain united by a connecting rod (15) which pivots at its ends on the male and female branches (6), (11).

The connecting rod (15) consists of two elements which move one compared to each other. In this embodiment, it can be seen that the connecting rod (15) is consists of a female hoop (1) which pivots on a pin (A) on the branch female (11) and which serves as an external guide to a male hoop (2) which slides the inside and pivots on the male branch (6) by means of a pin (B). The two hoops (1), (2) are connected by a spring (3).

There is in the inner hoop (2) a stop pin (4) guided in a window (16) of the outer hoop (1), although they can be conversely, or provide the device with any other conventional means of stroke limitation between the two frets (1), (2).

One of the two frets (1), (2) at least is under the action of a spring. In this case, there is a spring (5) joined to the outer hoop (1) and to the female branch (11) pivotally (C) its pivoting axis (C) being preferably between the pivot pin (A) of the outer hoop (1) and the pivot axis (21) of the lug (14).

a).- Lorsqu'il se déplace dans la fenêtre (8), il glisse sur les dents (9) de cette fenêtre (8).

b).- L'enchâssement de ses dents (17) avec les dents (9) de la fenêtre (8) n'a lieu que lorsque l'extrémité (e) de sa tête (c) est en contact avec les dents (9), ce qui permet l'avancée de l'axe (21) de l'ergot (14) et l'enchâssement en résultant des dents (17) de l'ergot avec les dents (9) de la fenêtre (8).

Additional problems with known clamps arise from the lug (14), since:

a) .- When it moves in the window (8), it slides on the teeth (9) of this window (8).

b) .- The embedding of its teeth (17) with the teeth (9) of the window (8) takes place only when the end (e) of its head (c) is in contact with the teeth ( 9), which allows the advancement of the axis (21) of the lug (14) and the ensuing embedding of the teeth (17) of the lug with the teeth (9) of the window (8) .

In the invention, we have arranged in the window (8), near the teeth (9), a sliding track (19) where a finger (18) slides which protrudes from the head (c) of the lug (14), so that the lug (14) is no longer in contact, when it displacement, with the teeth (19), and the pivoting of the lug (14) on its axis is as small as you want, because it will depend on the separation (Δ) of the finger (18) by in relation to the sliding track (19), thereby producing a tightening faster and without wear of the lug (14).

This, joined to the fact that the pivoting of the connecting rod (15) of its rest position (α) or open clamp (Figure 1) in its closed clamp position (figure 2) is very weak (around 4 °), gives rise to manual action (F) on the branches for clamping the workpiece (20) have a stroke much less than the one that was known until now.

Claims (3)

Self-adjusting pliers, consisting of a male and a female branch, with toothed jaws and sliding relative to each other, by means of a lug element, which encases them and slides in a longitudinal and toothed window made in one of the toothed jaws, the two branches being joined by a connecting rod, which is characterized by the fact that it consists of: a) .- Two frets (1), (2), which move relative to each other telescopically, one (2) of them pivoting on the male branch (6) and l 'other on the female branch (11); b) .- A first spring (3) which embeds the two frets (1), (2) and: c) .- A second spring (5) which unites one (1) of the frets to one (11) of the branches. Self-adjusting pliers, according to the preceding claim, characterized by having a travel limiter (4) between the two frets (1), (2). Self-adjusting pliers, according to the first claim, characterized by the fact of having, in the longitudinal wall, the window (8) a sliding track (19) for a finger (18), which protrudes from the head (c) of the lug element (14), a predetermined separation (Δ) being established in the open clamp position between this finger (18) and this sliding track.

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