EP3696132A1 - Safety load hook - Google Patents

Abstract

In the case of a safety load hook (1) with a lower part (2) which forms a curved hook mouth (3) with a hook opening (4) of a predetermined nominal width (s) and which is in an open position in which the hook opening (4) can be inserted or removing a load is open, and in a closed position pivotable upper part (5) is attached, in which it covers the hook opening (4) so that the introduction of a load into the hook mouth (3) or the removal of a load contained therein from this is prevented, a marking (8, 9) is provided on each of the end areas (6, 7) of the upper part (5) and lower part (2) facing each other when the upper part (5) is in the closed position, whereby in the closed position of the upper part (5 ) if the size of the hook opening (4) corresponds to its nominal width (s), the marking (9) on the lower part (2) is offset from the marking (8) on the upper part (5) by a distance in the direction of the hook opening (4), which is chosen so that both Markersu ngen (8, 9) when a predetermined maximum expansion of the hook mouth (3) occurs compared to its predetermined nominal width (s) in the closed state of the upper part (5) lie directly next to one another.

Description

The invention relates to a safety load hook, comprising a lower part which forms a curved hook mouth with a hook opening of a predetermined nominal width and on which an upper part that can be pivoted into an open position, in which the hook opening is open for inserting or removing a load, and into a closed position is attached, which in this covers the hook opening to the outside so that the introduction of a load to be picked up in the hook mouth or the removal of a load contained therein is prevented.

With such safety load hooks, however, it is necessary to ensure that they are always in a safe condition in the context of recurring tests. A key point here is to check the deformation of the hook mouth, which z. B. occurs in the event of overloads. So z. B. in accordance with EN 818-6 and ÖNORM M9611, the permissible widening of the hook mouth due to overloading is 10% of its nominal size, which must always be checked as part of the recurring tests.

A common checking method is to first determine the nominal width of the hook opening according to the manufacturer's specifications or with the aid of a product catalog and then to measure the actually existing hook opening with a suitable measuring device. The widening of the hook mouth that has already occurred can be determined from the resulting difference, after which it can be decided whether the safety load hook has already reached the deformation limit and is to be eliminated. In addition to the measurement to be carried out, a corresponding computational effort has to be carried out in order to be able to make the final decision.

Safety load hooks have also become known in the market in which forged wear marks are attached to the lower part of the hook in the area of the hook mouth, to the left and right of this. An additional text is attached there that defines a maximum distance between these two markings. When the hook mouth widens and reaches the specified maximum distance for the maximum permitted mouth opening the safety load hook must be eliminated. Here too, however, it is necessary to measure the distance by means of a suitable measuring device in order to be able to determine when the hook is ready for discard.

In both of the above-mentioned cases, it is necessary to be able to use at least always a suitable measuring device in order to determine whether the hook in question is already excessively deformed or not.

Based on this, the invention aims to provide an improvement in the design of the hook in order to save both the measurement of a distance and thus time for the ongoing tests and to be able to carry out a purely visual inspection.

According to the invention, this is achieved with a safety load hook of the type mentioned in that a marking is provided on each of the end regions of the upper part and lower part facing each other when the upper part is closed, with the marking on the lower part being changed from the marking on the upper part in the closed position of the upper part a distance is offset in the direction of the hook opening, which is chosen so that both markings are aligned directly next to one another when a predetermined maximum widening of the hook mouth occurs compared to its predetermined nominal width in the closed state of the upper part.

The wear indicators in the form of corresponding markings attached to the safety load hook according to the invention both on the upper part of the hook and on the lower part are in the new condition of the safety load hook, i.e. when the hook opening still has the specified nominal width, so that when the upper part of the hook is closed, they are not in a line, but are offset from each other at a distance. If, however, the hook mouth widens in the course of use as a result of deformation, for example due to overloading, the distance by which the two markings are offset from one another is smaller when the upper part is closed, and when a predetermined size of the widening is reached, the two markings are aligned directly next to each other. In this way, when carrying out a safety check, the tester can immediately visually recognize that the hook in question has reached the permissible deformation limit and must be eliminated if the two markings are directly next to each other when the permissible deformation limit is reached, i.e. when a predetermined size of the widening of the hook mouth occurs and there is no longer any distance between them, seen in the plane of the hook opening.

In order to be able to carry out this check, the examiner neither needs to use a suitable measuring device to determine the size of the opening of the hook mouth, nor is any computational effort required.

In addition, this visual inspection can also be carried out optically extremely quickly and requires almost no expenditure of time.

In the safety load hook according to the invention, the wear marks on the upper part and the lower part can be provided or attached in any suitable form, but it is particularly advantageous to forge them on the upper part and the lower part during manufacture.

A particularly preferred design of the wear markings is that they are each designed in the form of a line and, if they are directly next to one another, run in a common line which optically shows that the permissible deformation limit has been reached very quickly.

It is also advantageous if, in the invention, the distance between the markings is chosen so that they are next to each other in the closed position of the upper part when the hook mouth is widened by 10% compared to its specified nominal width, because this is usually the case when widened by this size During the ongoing review, it is necessary to determine whether the relevant safety load hook is ready for discard.

• Fig. 1 eine Seitenansicht eines erfindungsgemäßen Sicherheitslasthakens (in geschlossener Stellung);
• Fig. 2 eine Darstellung des unteren Bereiches des Sicherheitslasthakens aus Fig. 1 (im Schließzustand);
• Fig. 3 und 4 jeweils eine vergrößerte Darstellung der Einzelheit A aus Fig. 2, wobei
• Fig. 3 den Fall des Neuzustands des Sicherheitslasthakens aus Fig. 2 und
• Fig. 4 den Fall des Erreichens der Verformungsgrenze bei einem Lasthaken gemäß Fig. 2
  zeigen.

The invention is explained in more detail below with reference to the drawings in principle by way of example. Show it:

• Fig. 1 a side view of a safety load hook according to the invention (in the closed position);
• Fig. 2 a representation of the lower area of the safety load hook Fig. 1 (when closed);
• Figures 3 and 4 each an enlarged representation of the detail A from Fig. 2 , in which
• Fig. 3 the case of the new condition of the safety load hook Fig. 2 and
• Fig. 4 the case of reaching the deformation limit for a load hook according to Fig. 2
  demonstrate.

In Fig. 1 a side view of a safety load hook 1 according to the invention is shown, which comprises a fixed lower part 2 and an upper part 5 which is attached to the lower part 2 so as to be pivotable about a swivel joint 10.

The upper part 5 is provided with a suitable connection (above), for. B. with a dome connection (as in Fig. 1 shown) or with an eyelet or a swivel (not shown in the figures).

Here, the upper part 5 around the swivel joint 10 can be both in a closed position ( Fig. 1 ) are pivoted, as well as into an open position (not shown) in which the upper part 5 is opened upwards relative to the lower part 2 about the swivel joint 10.

The lower part 2 forms a hook mouth 3 which defines a hook opening 4 at the top, which when new has a predetermined nominal width n .

How out Fig. 1 can be seen, in the closed state of the upper part 5, the hook opening 4 is covered to the outside, while in the open state of the upper part 5, when this is folded up from the lower part 2, from the outside through the hook opening 4 a (not shown) load into the Hook mouth 3 can be brought in or removed from this again to the outside.

When the upper part 5 is closed ( Fig. 1 ) is at the end area 6 of the upper part 5 and the end area 7 of the lower part 2, which face each other in the closed state of the safety load hook 1 (whereby they can lie on top of each other or also a small distance from each other, approximately up to 3 mm, with a corresponding minimum opening according to EN 818-6 is permissible), one marking is provided in each case, namely marking 8 on upper part 5 and marking 9 on lower part 2. This is shown in the illustration of Fig. 2 that only made a lower section of the view Fig. 1 shows, indicated as detail A and, on an enlarged scale, for two different states in the Figures 3 and 4 each reproduced on an enlarged scale.

The representations of the Figs. 1 to 3 show a state in which the hook opening 4 has the specified nominal width n assigned to the relevant safety load hook 1, that is to say a state which corresponds to the new state of such a safety load hook 1. In the closed state, the end regions 6 and 7 of the upper part 5 and lower part 2 are aligned with their mutually facing ends, as shown in the illustrations in FIG Figures 1 , 2 and 3 show in detail, with express reference being made to the graphic representation in these figures.

In this state corresponding to the new state of the safety load hook 1, in which the lower part 2 and upper part 5 have the design dimensions assigned to them and the hook opening 4 has its assigned nominal width n , as shown in FIG Fig. 3 in an enlarged view of the detail A. Fig. 2 is shown, the wear marks 8 and 9 are attached to the upper part 5 and lower part 2 in such a way that the wear mark 9 on the lower part 2 relative to the wear mark 8 on the upper part 5 in the direction of the hook opening 4 by a distance a (cf. Fig. 3 ) is offset.

In the case of the safety load hook 1, however, during its service life, the loads held in the hook mouth 3 cause a continuous deformation of the hook mouth 3, in particular in the case of overloads, such that it expands. If a permissible size of the widening of the hook mouth and thus a corresponding deformation limit is reached, the safety load hook may no longer be used and must be eliminated. The permissible widening of the hook mouth 3 is specified for such safety load hooks 1 in detail by appropriate regulations or standards. B. in accordance with EN 818-6 and ÖNORM M9611 corresponds to a widening of the hook mouth 3 by 10% compared to its specified nominal width n .

When the hook mouth 3 is widened, its end region 7 facing the upper part 5 migrates outwards in the direction of the hook opening 4, as shown by the arrow F in FIG. Fig. 4 shows the detail A for the case that the deformation limit of the hook mouth 3 is reached.

The wear marks 8 and 9 are in the Figures 1 to 3 shown initial state of the safety hook 1 in its closed position, so according to its new condition, attached so that the offset of the wear mark 9 on the lower part 2 relative to the wear mark 8 on the upper part 5 is chosen so that the distance between the two a is just as large that the two Wear marks 8 and 9 when the maximum permissible widening of the hook mouth 3 is reached lie directly next to each other (or perhaps better said: one above the other), as shown in FIG Fig. 4 is shown.

The markings 8 and 9 are each, as the figures show, formed in a straight line shape and provided on the respective upper part 5 or lower part 2 carrying them that they when the predetermined maximum allowable expansion of the hook mouth 4 is reached, as they Fig. 4 shows run in mutual alignment along a common line b .

In this way, when checking the widening of the hook mouth 3 of such a safety hook 1, it is very easy for the examiner to immediately recognize that the maximum allowable widening of the hook mouth 3 (and thus also the hook opening 4) has been reached, because then the markings 8 and 9 are aligned directly with one another as shown in FIG Fig. 4 .

In other words: as long as the marking 9 is still laterally offset relative to the marking 8 in the direction of the hook opening 4 or the hook mouth 3, it can immediately be seen optically that the permissible widening of the hook mouth 3 has not yet been reached.

The wear markings 8 and 9 can be provided in any suitable form on the upper part 5 or lower part 2, whereby it is particularly advantageous if the respective mark 8 or 9 on the upper part 5 or lower part 2 is forged during its manufacture .

Claims (4)

Safety load hook (1), comprising a lower part (2) which forms a curved hook mouth (3) with a hook opening (4) of a predetermined nominal width (s) and on which one is in an open position in which the hook opening (4) can be inserted or Removing a load is open, and in a closed position pivotable upper part (5) is attached, in which it covers the hook opening (4) to the outside so that the introduction of a load to be picked up in the hook mouth (3) or the removal of one contained there Load from this is prevented, characterized in that a marking (8, 9) is provided on each of the end regions (6, 7) of the upper part (5) and lower part (2) facing one another when the upper part (5) is in the closed state, whereby in the closed position of the upper part (5) with a size of the hook opening (4) corresponding to its nominal width (s) the marking (9) on the lower part (2) from the marking (8) on the upper part (5) by a distance (a) in Direction (F) to the hook opening (4) is offset, which is chosen so that both markings (8, 9) when a predetermined maximum widening of the hook mouth (3) occurs compared to its predetermined nominal width (s) when the upper part (5) is closed. Safety load hook according to Claim 1, characterized in that the markings (8, 9) are forged on the upper part (5) and the lower part (2). Safety load hook according to Claim 1 or Claim 2, characterized in that the markings (8, 9) are each designed in line form and, when they are directly adjacent to one another, run in a common line (b). Safety load hook according to one of Claims 1 to 3, characterized in that the spacing (a) of the markings (8, 9) from one another in the closed position of the upper part (5) is selected so that when the hook mouth (3) is widened it is 10% of the specified nominal size (s) are next to each other.

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