GB2134622A

GB2134622A - Component, in particular a shackle

Info

Publication number: GB2134622A
Application number: GB08403132A
Authority: GB
Inventors: Reinhard Smetz; Helmut Speich
Original assignee: RUD Kettenfabrik Rieger und Dietz GmbH and Co KG
Current assignee: RUD Kettenfabrik Rieger und Dietz GmbH and Co KG
Priority date: 1983-02-08
Filing date: 1984-02-07
Publication date: 1984-08-15
Also published as: IT8420783V0; DE3304603A1; DE3304603C2; IT8419512A0; GB8403132D0; GB2134622B; IT1175321B; SE8400612L; SE8400612D0; SE459362B

Abstract

In the case of a component designed, in particular as a shackle, two limbs (2, 3) having bores (4, 5) are bridged by a bolt (9). One of the bores (bore 5), serving to accommodate the bolt, has a cylindrical portion (6) and an internally screw-threaded portion (7). At its end, the bolt has an exterior screw- thread (8) which can be screwed into the interior screw-thread of the bore (5). In its operating position, however, the bolt is supported in the bore only by way of a cylindrical bolt portion (10). <IMAGE>

Description

SPECIFICATION Component, in particular a shackle The invention concerns a component, in particular a shackle, with two limbs which contain bores for accommodating a bolt which bridges the limbs and takes up carrying forces directed transversely of the iongitudinal axis of the shackle and which is provided at one of its ends with an exterior screw-thread which is associated with an interior screw-thread formed in one of the bores and which is retained in its fitted positions by a securing element.

Shackles are known which comprise a limb having a cylindrical bore and a limb having a screw-threaded bore. The bolts of such shackles tend to fracture when heavy loading occurs in the zone where the cylindrical part of the bolt joins its screw-threaded portion. The fractures are caused by stress concentrations at the zone where the screw-threaded part and the cylindrical part of the bolt join each other. Fractures of this kind can be avoided in another described type of shackle wherein cylindrical portions of the bolt are mounted in cylindrical bores in the limbs and a screw-threaded bolt-end projects beyond the outer face of one of the limbs so as to form a screw-threaded pin for receiving a check nut which can be secured by means of a cotter, which can be inserted into a transverse bore in a part of the bolt end that projects beyond the check nut.

Although an arrangement of this kind is not affected by dynamic bending loads, it suffers from the disadvantage that the check nut can easily become lost and the cotter can be damaged not only by external loads but also by becoming screwed into the thread of the check nut.

In a further known arrangement and for the purpose of preventing the check nut from becoming mislaid, this nut is welded to the limb concerned. The effort required for aligning the check nut is consequently comparatively great, since the check nut must be so adjusted by a loaded bolt serving as gauge that no appreciable forces act upon it at a later stage. Furthermore, this arrangement does not ensure that the zone at which the screw-thread and the smooth bolt adjoin each other is safely relieved of load.

The object of the invention is to provide a component of the type in question that can be produced at little cost, can withstand a high load, particularly a dynamic load, and can be retained in a particularly advantageous manner in the operating position. According to the invention, this object is achieved in that the bore provided with the interior screw-thread has a cylindrical portion which is presented to the inside of the shackle and into which projects a cylindrical portion of the bolt, and in that in the operating position of the bolt, the carrying forces are transmitted from the bolt to the shackle solely by way of cylindrical portions of the bore and of the bolt.

The component according to the invention is distinguished by its high strength. Stresses due to notch effect in the zone where the screw-threaded portion and the cylindrical part of the bolt join each other are safely eliminated. Considerable reduction in manufacturing costs is achieved as compared with the arrangement comprising a welded-on check nut. Last but not least, savings are particularly great, since the components of the kind under consideration can be mass produced.

Particular advantage accrues if a groove is provided between the cylindrical portion of the bolt and its exterior screw-thread, which groove can be used to secure the bolt when it is in its fitted position.

The component of the invention permits the application of high loads. To prevent the bolt, designed for such loads, from being replaced by a standard bolt, it is recommended that the screwthread should have a pitch greater than that of a metric thread or inch thread, so that it is not possible for standard bolts to be screwed into the limb of the shackle.

Further features and details of the invention will be seen from the subsidiary claims and the following description of two embodiments illustrated in the attached drawings, in which: Fig. 1 is a plan view, partly in section, of a first component, Fig. 2 is a plan view of that part of the component that is illustrated in section in Fig. 1, Fig. 3 is a first side view of the component, Fig. 4 is a second view of the component, Fig. 5 illustrates the relationship between the dimensions of one of the ends of the bolt, and those of the bore for receiving it, Fig. 6 is a plan view, partly in section, of a second component, Fig. 7 is a side view of the Fig. 6 component, and Fig. 8 illustrates the relationship between the dimensions of one of the ends of the bolt, and those of the bore for receiving it.

In Figures 1 , 3 and 4, the numeral 1 designates a component constituting a shackle which has two limbs 2 and 3 having bores 4 and 5. The bore 5 has a cylindrical portion 6 and a portion having an interior screw-thread 7. Projecting into the zone of the interior screw-thread 7 is a portion of a bolt 9 that has an exterior screw-thread 8, said bolt also having a cylindrical portion 10. The cylindrical portion 10 is supported in the bores 4 and 5.

The portion having the exterior screw-thread 8 is separated from the cylindrical portion 10 of the bolt 9 by a groove 11. Located in the zone of the groove 11 is a transverse bore 1 2 for accommodating a securing element 13 in the form of a clamping sleeve.

The interior screw-thread 7 is provided in an attachment 14 associated with the limb 3. The attachment 1 4 has at least two parallel outer faces 15 and 16 to which a key can be applied and each of which can serve as a bearing while the securing element 13 is being forced in.

As can be seen from Figure 5, the play a between the cylindrical portions 10 and 6 of the bolt 9 and the bore 5 is considerably smaller than the backlash A between the screw-threads 7 and 8. The transmission of forces between the limb 3 and that portion of the bolt 9 provided with the screw-thread 8 is thus eliminated. The screwthread 8 is fully relieved of load when radial load is applied to the bolt 9. It simply performs the function of providing axial support in the event of inclined pull or excessively great deflection. The backlash A depends upon the depth H of the screw-thread. The greater this depth H, the greater can be the backlash A. In order to increase H, the pitch of the screw-thread is made greater. The consequence of the unusually great pitch is that bolts having standard screw-threads, as used for normal shackles, cannot be combined with the component described.The great play between the threads also offers the advantage that the functional reliability of the described component cannot be adversely affected by contaminating material or subsequent hot galvanizing.

The securing element 13 is arranged in a manner in which it is protected. If a fixing means that is effective for only a short time is required, the element 13 can be replaced by a resilient plug such as is referred to in DIN 11 024.

In Figures 6 and 7, the numeral 17 designates a component, again designed as a shackle, the limbs 18 and 19 of which are bridged by a bolt 20. The limbs 18 and 19 have bores 21 and 22, the bore 22 having two cylindrical portions 23 and 24 which are arranged at opposite sides of an interior screw-thread 25. The bolt 20 is also provided with an annular groove 26, which separates its cylindrical portion 27 from a portion having an exterior screw-thread 28. Here again, a securing element 29 holds the bolt 20 in its operating position in which there is no contact between the exterior screw-thread 28 and the cylindrical portion 24 of the bore 22; this is shown in particular in Fig. 8 in which g is the distance between, on the one hand, the tips of the exterior screw-thread 28 and, on the other, the portion 24.

To prevent unwanted disengagement of the screw-threaded portions, i.e. to retain the bolt 20 in its working position when under load, F must be greater than f.

Claims

1. A component, in particular a shackle, with two limbs containing bores for accommodating a bolt which bridges the limbs and takes up carrying forces directed transverseiy of the longitudinal axis of the shackle and which is provided at one of its ends with an exterior screw-thread associated with an interior screw-thread formed in one of the bores and which is retained in its fitted position by a securing element, in which the bore provided with the interior screw-thread has a cylindrical portion which is presented to the inside of the shackle and into which projects a cylindrical portion of the bolt, and in which, in the operating position of the bolt, the carrying forces are transmitted from the bolt to the shackle solely by way of cylindrical portions of the bores and of the bolt.

2. A component according to claim 1, in which a groove is provided between the cylindrical portion of that end of the bolt having the exterior screw-thread, and this exterior screw-thread.

3. A component according to claim 2, in which when the bolt is in the fitted position, the groove is in alignment with a transverse bore for the securing element.

4. A component according to claim 3, in which the diameter of the transverse bore is iess than the width of the groove.

5. A component according to claims 1 to 4, in which the securing element is formed by a clamping sleeve.

6. A component according to claim 2, in which the interior screw-thread of the bore is located in the zone of the groove in the operating position of the bolt, the length of the interior screw-thread being smaller than the width of the groove, and the bore also having a cylindrical portion direct towards the outside of the limb.

7. A component according to claim 6, in which the play of the bolt in the cylindrical portion of the bore which is directed towards the inside of the limb is so great that the axis of the exterior screwthread of the bolt that is screwed through the interior screw-thread is offset relatively to the axis of the interior screw-thread by an amount which prevents the exterior screw-thread from being unscrewed when the bolt is loaded.

8. A component according to any one of claims 1-7, in which the play between the cylindrical portions is less than the backlash between the screw-threads of the bolt and the bore.

9. A component according to any one of claims 1-Bin which the screw-threads have a pitch which is greater than that of metric threads and inch threads.

10. A component according to claim 9, in which the pitch of the threads of the bore and of the bolt is at least equal to 1.2 times the pitch of standard threads.

11. A component according to any one of claims 1-10, in which the limb with the bore having the interior screw-thread has an attachment near which the interior screw-thread is located.

12. A component according to claim 11, in which the attachment is provided with at least two parallel outer faces.

13. A component according to claim 12, in which the parallel outer faces extend at right angles to the transverse bore for a securing element.

14. A component according to claim 1 substantially as described herein with reference to Figures 1-5 or Figures 6-8 of the accompanying drawings.