EP1561702A1

EP1561702A1 - Clamp

Info

Publication number: EP1561702A1
Application number: EP05380010A
Authority: EP
Inventors: Juan Manuel Benito Navazo
Original assignee: Unex Aparellaje Electrico SL
Current assignee: Unex Aparellaje Electrico SL
Priority date: 2004-02-05
Filing date: 2005-01-17
Publication date: 2005-08-10
Anticipated expiration: 2025-01-17
Also published as: EP1561702B1; ES2388336T3; ES1056663U; ES1056663Y

Abstract

Clamp of automatic tie constituted by a monopiece comprising a strap (3) provided in its lower face of a toothed area (6) and a locking head (2) provided with two facing side walls (4) and a tilting toothed ratchet (5). In the operative position, the strap (3) forms a loop and traverses the locking head (2) between its side walls (4), acting then the tilting toothed ratchet (5) on said toothed areas (6). The side walls (4) have weakened areas (7) which locally reduce the moment of inertia of the side walls (4) resistant to bending in the longitudinal direction of the clamp, so that when strongly tightening the clamp about an object a local bending of said locking head (2) is obtained at the level of said weakened areas (7).

Description

Field of the invention

This invention relates to a clamp, in particular, one of the type formed by a monopiece, made, for example, by injection of a synthetic thermoplastic material, that are especially used in the field of electrical installations and which is composed by a locking head and a flexible strap.

In the present case, it refers to clamps of the type above mentioned, known as clamps with tangential locking head, that is, in which the locking head is formed so that the passage provided in it in order to insert the strap goes along said locking head and it is maintained, along with the latter, parallel to said strap in its operative position.

State of the art

Many embodiments of clamps that provide tangential locking heads are known, as for example the ones that are the object of Spanish utility models ES248452U, ES254661U and ES271277U and US patents US5745958 and US5890265. These known clamps are ineffective for clasping elements of small section.

The clamps commonly used, as the ones above mentioned, have their locking heads as substantially rigid elements that, despite their relative reduced length, do not adapt to the periphery of the assemblies to be tighten when the last have a small section. On the other hand, their straps have the same flexibility along all its length, showing a higher rigidity near its junction with the locking head, thereby making difficult either insertion of the free end of the strap in the snout of the locking head, as crossing the locking head to carry out the locking in the operative position, as the adaptation of the strap to an assembly with small section.

Summary of the invention

In order to overcome the above disadvantages of the clamps in question, it has been adopted the solution of forming the locking head, and optionally also the strap, so that its moment of inertia resistant to bending in the longitudinal direction is locally reduced, providing a local flexibility that allows the correct tightening of the clamp to any assembly to be fixed, and, in particular, to the ones of very small section.

The clamp according to the invention is a clamp of automatic tie constituted by a monopiece comprising a locking head and a strap provided in its lower face with a toothed area, having said strap a free end and a joint end inserted in said locking head, being provided said locking head with two facing side walls and one tilting toothed ratchet, so that in the operative position of said clamp said strap forms a loop and traverses said locking head between said walls in the longitudinal direction of the clamp, acting then said tilting toothed ratchet on said toothed area. The clamp according to the invention is characterised in that said side walls have weakened areas which locally reduce the moment of inertia of said side walls resistant to bending in the longitudinal direction of the clamp, so that when the clamp is tighten about an object a local bending of said locking head is obtained at the level of said weakened areas.

In the present description, as well as in the claims, by longitudinal direction of the clamp must be understood the longitudinal direction defined by the strap when the clamp is arranged flat, that is with the strap extending in a straight direction, which is then said longitudinal direction. On the other hand, when referring to a lower face or edge, either of the strap or of other part of the clamp, it must be understood that it is a face or edge internally located at the loop formed by the clamp in its operative position tightening an object. Analogously, when referring to an upper face or edge it must understood that it is a face or edge that is externally located to said loop.

Preferably, said weakened areas are located in the lower edge of said side walls and they consist in notches defining a hollow transverse space in said locking head.

The invention also considers the case in which said weakened walls are arranged in the upper edge of said side walls. Actually, this alternative is an equivalent form to the previous one, by which the aim of the invention is also reached, obtaining the same effect.

Advantageously, said notches have a bowed form in the longitudinal direction of the clamp.

Preferably, said side walls of the locking head have facing faces which are mutually connected by an inclined crossbar, a receded crossbar and said joint end of the strap, being free the edge of said joint end, delimiting said inclined crossbar and said receded crossbar a threading mouth for the free end of said strap, and being said notches located, with respect to the longitudinal direction of said clamp, between said free edge of the joint end of the strap and said inclined crossbar.

Advantageously, said tilting toothed ratchet is formed by an extension in cantilever slightly bent extending from said inclined crossbar, and is preferably engaged between two symmetric ribs provided in the facing faces of said side walls.

Preferably, the free edge of said joint end of the strap has a rounded form.

Advantageously, said notches separate the lower faces of said side walls in two planes forming an obtuse angle, being the first of said planes coplanar with said joint end of the strap and being the second one of said planes coplanar with a lower face of said inclined crossbar.

In a preferred embodiment, the external faces of said side walls of the locking head are convex and they are provided with serrations extending transversally to the longitudinal direction of said clamp.

Optionally, it can be foreseen to provide said locking head with a visor extending between the facing faces of said side walls as a continuation of said receded crossbar and in direction to the joint end of the strap.

Preferably, said strap is provided with a local structural arrangement which locally reduces the moment of inertia of said strap resistant to bending in the longitudinal direction of the clamp, being said local structural arrangement located near the junction of the strap with said locking head, so that when tightening the clamp about an object a local bending of said strap is further obtained at the level of said local structural arrangement.

Advantageously, said local structural arrangement is a dimple located at the lower face of said strap, between said toothed area and the junction with said locking head, extending said dimple along all the width of said strap, so that the strap has its minimum thickness at the level of this dimple.

Preferably, said strap has a tapered profile in its free end.

Brief description of the drawings

In order to understand better the above ideas, a preferred embodiment of the invention is now described with reference to the enclosed representing drawings. In the drawings:

Figure 1 shows, in a plan view, a clamp according to the invention.

Figure 2 shows, in a side elevation view, the clamp of figure 1.

Figure 3 shows, in a bottom view, the clamp of figure 1.

Figure 4 shows a centred longitudinal sectional view of the clamp of figure 1.

Figure 5 shows, in a view according to figure 1 in a higher scale, the clamp's head and a part of the strap.

Figure 6 shows, in a view according to figure 3 in a higher scale, the clamp's head and a part of the strap.

Figure 7 shows, in a view according to figure 4 in a higher scale, the clamp's head.

Figure 8 shows the object of figure 7 in a bending position when clamping an object of small section.

Figure 9 shows, in a perspective view, central and longitudinally cutaway, the clamp of figure 1.

Detailed description of one embodiment of the invention

As can be observed in figures 1 to 4, the clamp of the invention is formed by a monopiece that in this case is made of synthetic injected plastic composed by a locking head and a strap. This clamp is of the type of automatic tie, wherein the locking head comprises two side walls and a tilting toothed ratchet, which acts on a teeth extending along one of the faces of the strap that, in the operative position, forms a closed loop longitudinally traversing the locking head.

In clamp 1 shown in figures 1 to 4, one locking head 2 and a strap 3 are distinguished, both provided with a local structure that gives them a high flexibility. The locking head 2 is constituted by a body essentially formed by two side walls 4 and a tilting toothed ratchet 5. The strap 3 has a slightly higher width and a lower thickness than the common ones of conventional clamps. This modification of the straight section of the strap with respect to conventional clamps aims at reducing the moment of inertia resistant to bending along the most part of said strap without decreasing its tensile strength. The strap 3 is provided with a toothed area 6 in its lower face, which corresponds to the internal face of the loop formed by the clamp when it is in operative position tightening an object.

According to the invention, the locking head 2 has in longitudinal direction both weakened areas in the lower faces of the side walls 4. These weakened areas are materialised in two bowed notches 7 that locally reduce the moment of inertia of the locking head resistant to bending in the longitudinal direction.

On the other hand, also according to the invention, the strap 3 has, immediately next to the locking head 2, a local structural arrangement that locally reduces the moment of inertia resistant to bending and which consists in a transverse dimple 8. The strap 3 has, furthermore, its free end or tip of threading 15 made according to a tapered profile.

The locking head 2 has its two flat side walls 4 symmetric and substantially flat in their facing internal faces. These side walls 4 are mutually related by an inclined crossbar 9 acting as a threshold, a receded crossbar 10 acting as a sill, and the margins of the joint end 11 of the strap 3 that has a free rounded edge 12. The bowed notches 7 are arranged between said joint end 11 of the strap and the inclined crossbar 9. Furthermore, in both internal faces of side walls 4 are arranged guide ribs 13 that are mutually symmetric and are located at the level of teeth of the tilting toothed ratchet 5.

The locking head 2 has an oval plant of truncate poles that has its side walls 4 according to a cylindrical convex surface provided with serrations 14 with a nonslipping function in the moment of strapping the clamp 1. As shown in fig. 7, notches 7 separate the lower faces of the side walls 4 into two planes forming an obtuse angle 17. The first plane is coplanar with the joint end 11 of the strap, while the second plane is coplanar with a lower face of the inclined crossbar 9.

Finally, in figures 7-9 it is shown in a dash line a short visor 16 that can be optionally foreseen as a continuation of the crossbar of the receded crossbar 10 and which is aimed at covering the cut end of the strap 3 once the clamp 1 is installed.

Claims

Clamp (1) of automatic tie constituted by a monopiece comprising a locking head (2) and a strap (3) provided in its lower face of a toothed area (6), having said strap (3) a free end (15) and a joint end (11) inserted in said locking head (2), being provided said locking head (2) with two facing side walls (4) and with a tilting toothed ratchet (5), so that in the operative position of said clamp (1) said strap (3) forms a loop and traverses said locking head (2) between said side walls (4) in the longitudinal direction of clamp (1), acting then said tilting toothed ratchet (5) on said toothed area (6), characterised in that said side walls (4) have weakened areas (7) that locally reduce the moment of inertia of said side walls (4) resistant to bending in the longitudinal direction of the clamp (1), so that when tightening the clamp (1) about an object a local bending of said locking head (2) is obtained at the level of said weakened areas (7).
Clamp according to claim 1, characterised in that said weakened areas (7) are located at the lower edge of said side walls (4).
Clamp according to claim 1, characterised in that said weakened areas (7) are located at the upper edge of said side walls (4).
Clamp according to any of claims 1 to 3, characterised in that said weakened areas are notches (7) defining a transverse hollow space in said locking head (2).
Clamp according to claim 4, characterised in that said notches (7) have a bowed form in the longitudinal direction of the clamp (1).
Clamp according to any of claims 4 or 5, characterised in that said side walls (4) of the locking head have facing faces which are mutually connected by an inclined crossbar (9), a receded crossbar (10) and said joint end (11) of the strap, being free the edge (12) of said joint end (11), delimiting said inclined crossbar (9) and said receded crossbar (10) a threading mouth for the free end (15) of said strap (3), and being positioned said notches (7), with respect to the longitudinal direction of said clamp (1), between said free edge (12) of said joint end of the strap and said inclined crossbar (9).
Clamp according to claim 6, characterised in that said tilting toothed ratchet (5) is formed by an extension in cantilever slightly bent extending from said inclined crossbar (9).
Clamp according to claim 7, characterised in that said tilting toothed ratchet (5) is engaged between two symmetric ribs (13) provided in the facing faces of said side walls (4).
Clamp according to any of claims 6 to 8, characterised in that said free edge (12) of the joint end of the strap has a rounded form.
Clamp according to any of claims 6 to 9, characterised in that said notches (7) separate the lower faces of said side walls (4) into two planes forming an obtuse angle (17), being the first of said planes coplanar with said joint end (11) of said strap and being the second of these planes coplanar with a lower face of said inclined crossbar (9).
Clamp according to any of claims 1 to 10, characterised in that the external faces of said side walls (4) of the locking head are convex and are provided with serrations (14) extending transversally to the longitudinal direction of said clamp (1).
Clamp according to any of claims 6 to 11, characterised in that said locking head (2) is provided with a visor (16) extending between the facing faces of said side walls (4) as a continuation of said receded crossbar (10) and in the direction of the joint end (11) of the strap (3).
Clamp according to any of claims 1 to 12, characterised in that said strap (3) is provided with a local structural arrangement (8) which locally reduces the moment of inertia of said strap (3) resistant to bending in the longitudinal direction of clamp (1), being located said local structural arrangement (8) close to the junction of said strap (3) with said locking head (2), so that when tightening clamp (1) about an object a local bending of said strap (3) is further obtained at the level of said local structural arrangement.
Clamp according to claim 13, characterised in that said local structural arrangement is a dimple (8) located at the lower face of said strap (3), between said toothed area (6) and the junction with said locking head (8), extending said dimple (8) along all the width of said strap (3), so that said strap (3) has its minimum thickness at the level of said dimple (8).
Clamp according to any of claims 1 to 14, characterised in that said strap (3) has in its free end (15) a tapered profile.