Abstract:
Disclosed is a hook comprising a fork head ( 10 ) suitable to be connected to a high-strength round steel chain. A ring-shaped eye ( 14 ) is disposed next to the insertion slot ( 7 ) of the fork head ( 10 ), which is bridged by a cross bolt. The width (W 2 ) of said eye ( 14 ) is larger than the width (W 1 ) of the fork head&#39;s ( 10 ) insertion slot ( 7 ).

Description:
TECHNICAL FIELD  
       [0001]     The invention relates to a hook with a fork head which is suitable for connecting a high-strength round steel chain and of which the fork tines bound an introduction gap, of which the width is equal to 1.05 to 1.3 times the thickness of the links of the round steel chain and which is spanned by a cross-bolt adapted to the inner width of the chain link which is to be connected in each case.  
         [0002]     Hooks of the abovementioned type are used as attachment means which regularly form constituent parts of modular-constriction attachment systems with components which cannot be mixed up.  
         [0003]     Prior Art  
         [0004]     DE 8429724.7 U1 discloses a hook of the generic type of which the fork head has two rectilinear fork tines arranged parallel to one another. The facing sides of the fork tines bound an introduction gap or an introduction slot, of which the width is sufficiently large in order to accommodate the end link of a chain strand which has its strength coordinated with the strength of the hook. The combination of an excessively strong hook with the end link of a chain of low strength here is ensured by virtue of the thickness of the cross-bolt which spans the introduction gap being coordinated with the inner width of the end link of the respective chain strand, suitable graduations in the nominal thickness of the chains of systems which cannot be mixed up taking account of tolerances of the components which are to be combined. For cases where small graduations of the system components are important, it is known, from DE 3045209 C2, for the likewise essentially U-shaped introduction gap of a fork head to be defined in a step-like manner such that its width decreases in the direction of the base of the introduction gap.  
       DESCRIPTION OF THE INVENTION  
       [0005]     The known hooks are not fully satisfactory in so far as they are merely suitable for connecting to the end link of a chain strand. The object of the invention is to provide a hook to which other components of attachment systems can also be connected. This object is achieved according to the invention in that the fork tines of the hook in question, outside the region of the introduction gap, form an annular eye, of which the inside width is greater than the width of the introduction gap.  
         [0006]     The hook according to the invention provides the advantage that, in addition to end links of chain strands, it is possible to fit into its fork head, inter alia, suspension members, connecting members, eye hooks and shortening elements which are provided with a connection eye and, in a known manner, have flattened portions which allow them to be connected to connecting members which are designed in the manner of omega shackles with an introduction gap coordinated to the dimensions of chain links in a similar manner to the introduction gap of known fork-head hooks. It is thus possible, in contrast to known fork-head hooks, for a hook according to the invention which can be fitted into an eye of a point of attachment fastened on a load to be connected directly, without the interposition of a short chain-strand section and of a connecting member, to a suspension member for a crane hook, of which the dimensions, as is known, are usually considerably greater than hooks of the type according to the invention, which form constituent parts of an attachment system. If a ring bolt with a flattened portion is used as the point of attachment, it is also possible for the hook to be connected directly to the ring bolt and to be fitted into a suspension member designed as an end link of a suspension gear mechanism.  
         [0007]     Further features and details of the invention can be gathered from the subclaims and from the following description of two particularly advantageous embodiments of the invention which are illustrated in the attached drawing. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     In the drawings:  
         [0009]      FIG. 1  shows the rear view of a hook which is connected directly to a suspension member which is illustrated in side view and into which a crane hook can be fitted;  
         [0010]      FIG. 2  shows the side view of the hook according to  FIG. 1  connected to the sectionally illustrated suspension member according to  FIG. 1 ;  
         [0011]      FIG. 3  shows the side view of a hook according to the invention connected to an eye hook which is illustrated partly in section;  
         [0012]      FIG. 4  shows the rear view of the hook illustrated in  FIG. 3  and the side view of the eye hook connected thereto;  
         [0013]      FIG. 5  shows an overview illustrating the wide variety of possible uses of the hook according to the invention. 
     
    
     METHODS OF IMPLEMENTING THE INVENTION  
       [0014]     In  FIGS. 1 and 2 ,  1  is a suspension member which has a sufficient spacing and inner width to allow it to be fitted into the tine  2 , which is merely indicated in  FIG. 1 , of a crane hook, of which the cross section  3  largely fills the clear width of the suspension member  1 . The suspension member  1  is provided, in a known manner, with two flattened portions  4 ,  5 , the distance a between which is smaller than the width W 1  of the introduction gap  7  which is spanned by a cross-bolt  6  and belongs to a fork head  10 , which has two tines  8  and  9  and belongs to a hook  11  designed in accordance with the invention. In the case illustrated, the hook  11  and the suspension member  1  form a unit which can be utilized in order for an eye-containing point of attachment fastened on a load to be connected to a crane hook. In order to secure the suspension member  1  and hook  11  together, use is made of a stepped board  12 , which ensures the captive state of the cross-bolt  6 , and a clamping pin  13 . The width W 2  of the eye  14 , which is formed by the cross-bolt  6  and the hook tines  8  and  9 , and the inner width of the suspension member  1  make it possible for the latter to move without obstruction in the eye  14  both perpendicularly and parallel to the plane of the drawing.  
         [0015]      FIGS. 3 and 4  illustrate a unit which is formed from a hook  11  from  FIG. 1  according to the invention and by an eye hook  15  and can be utilized, for example, in order to connect the end link of a single-strand ring chain according to DIN 5688 Part 3 to an eye-containing point of attachment. As in the previously described case of the suspension member, in this case the eye hook  15  has, in the region of its eye  16 , two flattened portions  17 ,  18 , the distance a between which is smaller than the width W 1  of the introduction gap of the hook  11 . On account of the fact that the diameter D of the eye  16  is greater than the width B of the fork tines  8 ,  9 , movements between the hook  11  and the eye hook  15  are possible, once again, both in the plane of the drawing and perpendicularly to the, plane of the drawing.  
         [0016]      FIG. 5  documents the wide variety of possible uses of the hook  11  and the fact that, in contrast to the conventional fork-head hook  19  likewise depicted in this figure, it can be connected not just to the end link  20  of a more or less long chain-strand section  21 , but also—as has already been explained—to a suspension member  1 , an eye hook  11  and, in addition, to a connecting member  22 , a point of attachment  23 , a swivel hook  24 , a modified eye hook and to a shortening element  26 . It goes without saying that it is also necessary for the parts  22  to  26 , in the coupling region, to have flattened portions which allow them to be introduced into the introduction gap of the fork head of the hook  11 .