AT413585B - SHORTENING HOOK - Google Patents

Description

2

AT 413 585 B

The invention relates to a shortening hook for link chains, with a provided at its upper end fastening device, such. an eyelet or fork, a hook slot extending between a hook portion and a back portion of the hook perpendicular to the plane of symmetry of the hook for receiving a standing chain link and with sloping bearing surfaces on both sides of the plane of symmetry for chain links adjoining the stationary chain link.

A shortening hook of this type is described in the applicant's AT 391 927 (= DE 40 21 032 A1). Shortening hooks are used for hanging a chain, the io chain can not be hooked to the end link of the chain, but at any chain link and so the chain is "shortened" to the remaining piece of chain. In contrast to so-called claw hooks (such as those of AT 397 988 discussed below), the chain hooked in the shortening hook can be loaded on any chain end, or both, without damaging the chain, in particular the deformation of the chain Chain link, would lead.

In the cited document a fuse of the end of the chain is proposed, wherein at the lower end of the securing hook a fork is provided and the free-hanging end of the chain is hooked to this fork. The design of the slot - course 20 through the load axis of the hook - the risk that the held in the hook standing member is lifted, for example, by movements on the chain out of the hook, largely reduced. An additional backup of the chain was therefore considered not necessary so far. 25 However, the applicant's investigations have shown that, in contrast to the prevailing opinion, it is nevertheless possible, in special cases, for the chain to slide out of the shortening hook. For example, when the shortening hook is "turned upside down" and the slot opens downwardly, the chain will come off the hook during a load change. These applications, which have hitherto not been considered in detail, thus make it expedient to provide additional measures for securing a chain in a shortening hook of the type mentioned.

GB 1,497,504 discloses a safety hook consisting of a body part and a keeper1 with a pointed end. The closure member is rotatably mounted on the body member 35 by means of a pin and between a locking position in which the tail rests on the hook tip and the hook is thus closed, and an opening position in which the hook is open, is movable; By means of a locking bolt, the closing part can be locked in the locked position. Of course, it is in the safety hooks of this document to a simple round hook, which is not suitable for use as a shortening 40 hook.

In the applicant's AT 397 988 (= DE 42 36 599 A1) a secured claw hook for round steel chains is described. A claw hook is also used to shorten a chain, wherein a chain link of the chain to be shortened can be received in a pocket formed by the body of the claw hook; In this case, the chain runs along the plane of symmetry of the hook (in contrast to the shortening hook, wherein the chain runs transversely to the plane of symmetry). Therefore, a slot is provided in the hook for a subsequent chain link to this chain link, so that the hook portion of the hook is divided into two claw-like. The claw hook of the cited document has a load-bearing suspension piece, which is pivotally mounted on the hook body and lockable in a blocking position, wherein the lower part of the suspension piece is designed as a nose-like barrier extension in the blocking division of the recorded chain link from escaping from the bag prevents above. As already mentioned, a claw hook is disadvantageous because the hinged chain may only be loaded on the subsequent downward part of the chain. If the 55 chain on the other hand charged at the other end - which, according to experience, also in the operation. 3

AT 413 585 B occurs again and again by trained personnel - this easily leads to damage, in particular deformation, of the chain link received in the hook.

It is an object of the invention to provide a shortening hook in which the chain can be reliably secured against being lost from the hook slot. Here, the shape should be designed especially for profile steel chains.

The object is achieved by a shortening hook of the aforementioned type, in which according to the invention the hook is articulated into a hook body and a hook closure, wherein the hook body and closure are articulated to one another and pivotable relative to each other in the plane of symmetry between a securing position and a release position; Hook part and back are parts of the hook body and the fastening device is part of the hook closure, wherein in the securing position a securing lug of the hook closure the hook slot at the top at least partially closes and prevents 15 escape of the stationary chain link.

This solution according to the invention provides a reliable securing of the chain by adapting the known from safety hooks her concept of a closing part for the purpose of a shortening hook. 20

A preferred embodiment of the invention relates to the case that the shortening hook is used with profile chains whose chain links have a (at least outwardly) square cross-section. In this case, it is advantageous if the hook slot is designed with a flattened bottom for receiving a chain link of a profile chain with substantially flat outer edges. For a stable storage of the attached to the hook in the standing member standing chain links, it is sufficient if the height of the bearing surfaces for the adjoining the standing chain link chain links substantially equal to half the length of a Kettenglie-30 corresponds. In this case, it is favorable if the hook body is tapered in the region below the support surfaces to the plane of symmetry.

Furthermore, it is advantageous if the hook slot extends along a plane which is inclined towards the center line of the bearing surfaces, since the load can be received over the side surface of the stationary chain link.

In order to keep the play of the chain in the hook as small as possible, it is advantageous if the securing lug abuts in the securing position on an end face of the hook part. 40 In a further development of the invention, the head part in the securing position can be determined, by means of a locking piece for engaging the locking lug, wherein the locking piece has a locking surface of the head part associated holding surface and is pivotable by a projecting handle against the force of a return spring to to bring the holding surface out of engagement with the locking surface. 45

The invention together with further advantages will be explained in more detail below with reference to two embodiments, which are illustrated in the accompanying drawings. The drawings show: 50 55

1 and 2 are side views of a first embodiment of the invention, in the securing position (Figure 1) and in the release position (Figure 2) ..;

Fig. 3 is a front view of the hook of Figure 1 in the securing position.

Fig. 4 is a section along the line A-A in Fig. 2; and

Fig. 5 is a side view of a second embodiment.

According to FIGS. 1 to 3, a shortening hook according to the invention consists of a hook body 4

AT 413 585 B 1 (lower part) and a hook closure 2 (upper part). These two hook pieces 1, 2 are connected to one another by means of a joint 3 located at the upper end of the hook body 1, so that the hook closure 2 can be pivoted relative to the hook body 1 between a securing position (FIG. 1) and a release position (FIG. 2). 5

It should be noted that the terms "top" and "bottom" as used herein refer only to the usual orientation of the hook in a vertical chain hoist shown in the figures, but the hook can also be used in other arrangements, especially in horizontal chain hoists , 10

The shortening hook is completely symmetrical with respect to a plane of symmetry e (FIG. 3). The one-piece closure part 2 passes at its upper end in an Ose 4, which serves as a fastening device. A chain to be shortened (indicated by dashed lines in FIGS. 2 and 3) can be inserted into the hook body 1 transversely to the plane of symmetry e. 15

As can be seen in particular from FIGS. 1 and 2, a hook slot 7 extends between the hook part 5 and the back part 6 of the hook body 1 (integral in the exemplary embodiment shown) with the center plane h perpendicular to the plane of symmetry e of the hook. The hook slot 7 receives a stationary chain link 8, wherein the longitudinal axis of the chain link is perpendicular to the hook plane 20 e. For the two adjoining the standing chain link 8 chain links 9 sloping support surfaces 10 are provided on both sides of the plane of symmetry, which are inclined relative to the plane of symmetry. In order to enable a flat contact of the chain link 9 on a link side, the hook slot 7 or its center plane h is inclined relative to the center lines u of the subsequent chain links 9, and thus the median plane h 25 extends at a distance from the axis of the joint 3.

Advantageously, the hook is designed so that the other chain links 11 are free with respect to the hook. For this purpose, the support surfaces 10 are dimensioned so that they only the upper part - about half - the chain links 9 wear, so that the height H (Fig. 3) of the support surface 30 corresponds to 10 substantially half the length L of a chain link. Furthermore, the hook body 1 in the region below the support surfaces 10 - ie between the next chain links 11 - to the plane of symmetry e tapers.

The shortening hook shown is designed to accommodate a section steel chain in which the 35 links have flat outer edges. For this purpose, the hook slot 7 is designed with a flattened base 12; In addition, the upper edges (close to the plane of symmetry e) of the bearing surfaces 10 are pulled upwards as far as possible (FIG. 4) in order to enable a flat contact of the adjoining chain links 9. Fig. 4 shows a section through the hook body 1 along the line A-A of Fig. 1; For the sake of clarity, the components in the back part 6 are not shown in FIG. 4. The hook slot 7 is suitably at least as far as the thickness D of a chain link, but in any case narrow enough that can not pass through the chain, that is less than the width S (measured transversely to the longitudinal direction of the member, Fig. 5) of a chain link. For example, the width W of the hook slot 7 may be 1.1 to 1.3 times the chain link thickness D.

The upper part of the back part 6 is designed as a fork. The joint 3 is realized by means of an axle bolt 13 which is mounted in aligned through holes of the back part fork and a corresponding bore of the hook closure 2. In the space between the fork so below the joint also a locking piece 14 is provided for the hook closure 2, which will be discussed below.

The hook closure 2 has below the hinge 3 an extension in the form of a securing lug 15. In the securing position, the securing lug 15 closes the hook slot 55 upwards and thus limits the play of the standing chain link 8 in the hook slot 7.

Claims (5)

5 AT 413 585 B As shown in Fig. 1, proposes the locking lug 15 in the securing position with its tip 16 on an end face 17 of the hook part 5, so that movement of the two hook parts 1,2 is excluded in the securing position. (The end face 17 is hidden in FIG. 3 by the tip 16.) Even if the securing lug should not extend to the hook part 5, it is sufficient if the hook slot is limited in the securing position to such an extent that the standing chain link 8 escapes prevented. In the release position - Fig. 2 - on the other hand, the hook closure 2 is pivoted so far that a removal or insertion of a chain from or in the shortening hook prob-io lemlos is possible. As already mentioned, the hook closure 2 can be detected in the securing position. For this purpose a locking piece 14 is preferably used, which is pivotably mounted within the fork of the back 6 about an axis a and biased by means of a spring 18 in the sense of upward movement (i.e., counterclockwise in Figures 1 and 2). The locking piece 14 has a holding surface 19, which cooperates in the securing position with a latching surface 20 of the hook closure 2, and a handle 21 in the form of a trigger lever to allow an operator, e.g. with a finger to bring the locking piece against the force of the spring 18 in the position shown in Figure 2, whereby the Halteflä-20 surface 19 is brought out of contact with the locking surface 20; then a pivoting movement of the hook closure 2 against the hook body 1 in the release position shown in Fig. 2 is possible. Incidentally, reference should be made to the remarks of AT 397 988 with regard to the fixing piece. A second embodiment of the invention is shown in FIG. Therein, the fastening device of the hook closure 2 'is formed as a fork 22, in which an end member of a (not shown) upper chain can be hooked by means of a bolt. The axis b, c of the fastening device 4, 22 can in this case be perpendicular to the plane of symmetry e of the hook (FIGS. 1-3) or parallel to it (FIG. 5). 30 Claims: 1. shortening hook for link chains, with a fastening device provided at its upper end, e.g. an eyelet (4) or fork (44), a hook slot (7) extending between a hook part (5) and a back part (6) of the hook perpendicular to the plane of symmetry (e) of the hook for receiving a standing chain link (8) and with both sides the symmetry plane arranged, sloping bearing surfaces (10) for subsequent to the standing chain link chain links (9), 40, characterized in that the hook is divided into a hook body (1) and a hook closure (2), said hook body and closure articulated to each other and against each other in the plane of symmetry (e) between a securing position (Fig. 1) and a release position (Fig. 2) are pivotable, hook part (5) and back part (6) parts of the hook body (1) are 45 and the fastening device (4, 22) is part of the hook closure (2), wherein in the securing position, a securing lug (15) of the hook closure (2) at least partially closes the hook slot (7) at the top and un d prevents escape of the stationary chain link (8). 2. shortening hook according to claim 1, characterized in that the hook slot (7) is designed with flattened bottom (12) for receiving a chain link of a profile chain with substantially flat outer edges. 3. shortening hook according to claim 1 or 2, characterized in that the height (H) of the bearing surfaces (10) for the adjoining the standing chain link chain links 55 6 AT 413 585 B substantially equal to half the length (L) corresponds to a chain link. 4. shortening hook according to claim 3, characterized in that the hook body (1) is tapered in the region below the bearing surfaces (10) to the plane of symmetry (e). 5 5. shortening hook according to one of claims 1 to 4, characterized in that the hook slot (7) along a plane (h) extends, which is inclined against the center line (u) of the bearing surfaces (10). io 6. shortening hook according to one of claims 1 to 5, characterized in that the securing lug (15) abuts in the securing position on an end face (17) of the hook part (5). 7. shortening hook according to one of claims 1 to 6, characterized by a locking 15 piece (14) for locking the locking lug (15) in the securing position, wherein the locking piece has a locking surface of the hook closure (2) associated holding surface and by means of a projecting Handle is pivotable against the force of a return spring to bring the holding surface out of engagement with the locking surface. 20 For 2 sheets of drawings 25 30 35 40 45 50 55