GB2041441A

GB2041441A - Coupling device, in particular for clamping chains

Info

Publication number: GB2041441A
Application number: GB7944381A
Authority: GB
Original assignee: Eisen und Drahtwerk Erlau AG
Current assignee: Erlau AG
Priority date: 1978-12-23
Filing date: 1979-12-24
Publication date: 1980-09-10
Also published as: ATA800579A; IT1127718B; GB2041441B; NL7909049A; NO151719B; CA1141592A; SE7910559L; FR2444857A1; NO151719C; BR7908471A; NL188538B; SE426461B; YU309479A; FR2444857B1; NL188538C; NO794211L; AT379775B; IT7928054A0

Abstract

A coupling device for tyre chains comprises two relatively movable coupling members (1,3 and 3 min ) for receiving chain links and a releasable locking mechanism (7) for one of the coupling members in the form of a hook (1) which is movable into a release position under the force of the attached chain. The members (3,3 min ) are respectively attached to spindles (13) having oppositely handed threads and cooperating with a double nut (6) which is rotatable by a sleeve 10. A bifurcate clevis (2) spans the hook (1) opening and is releasably connected to the hook (1) which is shaped to provide a lever arm (x) between the pivot point (4) and the chain engagement point (16). The hook (1) extends beyond the pivot point (4) and the extension (15) is locked by a sleeve (7) slidably mounted on the device. The other pivoted member (3 min ) has a fork end and an indexing bolt (12) mounted across the fork end. A ratchet (23) may be provided for rotating the double nut 6 for use when high tensioning loads are involved. <IMAGE>

Description

SPECIFICATION Coupling device, in particular for clamping chains The invention relates to a coupling device, in particular for clamping chains, with two pivoted members for receiving chain links, which pivoted members are able to move relative to each other and comprise a releasable locking mechanism.

German Offenlegungsschrift 26 23 827 discloses a tensioning device which in conjunction with a releasable locking mechanism is intended to be used for tensioning tyre chains. This tensioning device has proved successful in practical use, although more than one operation is necessary for locking and unlocking. Thus, at least one securing pin must be released and removed and the chain must be lifted out of the pivoted member constructed in the form of a hook. For different situations, for example in the case of a disaster, this known tensioning device is too complicated. This is true above all when the tensioning device is to be used for tensioning clamping chains for any material to be clamped. There are instances when a plurality of unlocking operations are necessary in the shortest possible time.Furthermore, in addition to sufficient space, to a certain extent the use of auxiliary means are required for tensioning clamping chains, using the known tensioning device, likewise for unlocking.

It is the object of the invention to construct the coupling device so that it can be connected in a troublefree manner to the chains to be joined, without using auxiliary means and also once more released therefrom, in the case of particularly restricted conditions as regards space, with little work and in a short time.

This object is fulfilled according to the invention due to the fact that the pivoted members are held under tension in the closed position and at least one coupling member can be moved into a release position under the force of the attached chain.

Suitable developments of the idea of the invention will become apparent from the subclaims, description and drawings.

As a result of the construction according to the invention, without using additional tools, rapid and reliable locking, tensioning and unlocking of the clamping chain is possible.

However, it is also possible to use the coupling device in instances where little space is available for rotating the tensioning lock. Under the tension of the chain, the coupling members open automatically after releasing the respective locking mechanisms. All parts are easily accessible and reliable in operation, so that the coupling device according to the invention is also suitable for use in disasters.

In any case, in order to ensure that the coupling members are not rotated at the time of clamping, but retain their relative position with respect to the tensioning device during tensioning of the chains, according to a preferred feature of the invention, provided for moving. the coupling members are two spindles respectively with left and right-hand screw threads, the spindles being able to be moved in opposite directions by means of a double nut or turn-buckle and in which case a longitudinally slit tube for guiding the spindles is located between the spindles and the double nut. The spindles are guided in their longitudinal direction in the longitudinally slit tube, at the time of clamping, so that the coupling members connected to the spindles retain their position with respect to the tensioning device, during the adjusting operation.

Furthermore, positive opening of the spindles is achieved by means of the longitudinally slit tube, so that both spindles are moved in opposite directions simultaneously, under all circumstances.

Further features of the invention will become apparent from the description, claims and drawings.

The invention is described in detail hereafter with reference to some embodiments illustrated in the drawings: Figure 1 is a plan view of a coupling device according to the invention with swiveling hook comprising a securing sleeve and forklike coupling member; Figure 2 is a sectional view on line I-I of Fig. 1; Figure 3 is a plan view of a variation of the releasable locking mechanism with swiveling hook; Figure 4 is a sectional view on line Ill-Ill of Fig. 3; Figure 5 is an enlarged illustration of the point A according to Fig. 1, partly in section; Figure 6 is an enlarged illustration of the point B according to Fig. 2, partly in section; Figure 7 is a plan view of a further variation of the locking mechanism with spring-loaded contact part;; Figure 8 is a sectional view on line VII-VII of Fig. 7 with adjoining tensioning device with ratchet; Figure 9 is a side view in direction C according to Fig. 7; Figure 10 is a vertical section through the incorporated ratchet; Figure 11 is a longitudinal section through a further variation of a tensioning device; Figure 12 is a sectional view on line A-A of Fig. 11.

The tensioning device comprises two spindles 1 3 respectively with a self-locking left-hand and right-hand screw thread 22, which are mounted in a double nut 6. Serving for tensioning according to Figs. 1 and 2 is the knurled hand tube 10, which allows a transmission of force of approximately 4000N for example. For greater pretensioning forces, the provision of a ratchet, to be described hereafter, in place of a hand tube 10, is advantageous, see also Fig. 8. By rotating the hand tube 10 to the left and right, a tension ing distance of up to 75mm can be overcome.

The hand tube 10 is fixed to the double nut 6 by the locking pin 11. Rotation for tensioning the device is indicated by a mark "Close" let into the hand tube 1 0. The spindles 1 3 are protected from dust and dirt by a protective tube 5. An axial displacement of the parts is prevented by resiiient securing rings (Seeger rings) 8. The reference numeral 21 designates a stop pin.

All the parts of the tensioning device can be exchanged and are maintenance free. All the parts which are in direct engagement with external parts are accordingly heat-treated against wear. Even in the presence of a considerable amount of dirt, dust and the like, the tensioning device has a reliable operation.

1 6Mn Cr5 can be used as the material.

On one end face, the tensioning device according to the invention comprises a swiveling hook 1. The suspension opening formed by this hook 1 is spanned by the clevis 2. The hook 1 is located between two sides of a fork connection 3, which sides extend parallel to each other and project freely and the hook is mounted to swivel about the pivot point 4, the pivot point 4 being formed by a bolt.

The profile of the hook 1 is vital. It must be selected so that a lever arm x is formed between the pivot point 4 of the hook 1 and the point of engagement of the chain 1 6 in the hook 1, i.e. the traction of the chain must act eccentrically. Such a profile of the hook 1 contributes to more rapid unlocking. After releasing the locking mechanism of the swiveling hook 1, the latter swings downwards and thus immediately releases the inserted chain. This release of the chain 1 6 is assisted by the eccentric action of the traction of the chain in the hook 1. Thus, rapid and easy unlocking is ensured.

According to Figs. 1 and 2, the clevis 2 is likewise arranged to swivel about the pivot point. However, it may also be attached in a rigid manner. The clevis 2 is formed from two parts bearing on the sides of the fork connection 3 or located in the plane of the sides. The clevis 2 may have a straight construction or may be curved in the opposite direction to the hook 1. In this case it is important that the suspension opening formed by the hook 1 is spanned. If it is curved, the clevis 2, forms a ring with the hook 1, see Fig. 2.

According to Figs. 3 and 4, the two parallel sides of the fork connection 3 may be bent obliquely upwards and span the suspension opening formed by the hook 1. In this case, the bent sides serve as a rigid clevis 2. In this case, the swiveling hook 1 is detachably connected by its free end to the clevis 2. Any suitable connecting means may serve as a releaseable connection between the hook 1 and the clevis 2. In the example, a locking pin 19 is used. As can be seen from Figs. 3 and 4, the pivoted members can be incorporated on their own, without an actual tensioning device, as an independent component in the tensioning system.

However, in one embodiment of the invention, it is also possible to restrain the swiveling hook without loading the clevis 2. For this purpose, the hook 1 is extended beyond the pivot point 4, in which case the extended part is locked by the tensioning device, see Fig. 2.

This locking takes place by means of a sliding sleeve 7, which is mounted to move on the tensioning device. In the locked position of the hook 1, the sliding sleeve 7 is slid over the end of the extended part of the hook 1.

This end of the hook 1 has a profile 15, over which the correspondingly constructed part of the sliding sleeve 7 can be engaged. Since the sliding sleeve 7 is able to move on the tensioning device, the profile 1 5 of the hook 1 must extend parallel or virtually parallel to the outer wall of the tensioning device. The sliding sleeve 7 is mounted on a compression spring 9. With the provision of a sliding sleeve 7, rapid unlocking takes place solely by sliding the latter back. The extended part of the swiveling hook 1 is thus released and the hook 1 swings downwards, which also takes place under load. The chain 1 6 or clamping point is thus released.

According to Figs. 1 and 2, the fork connection 3 and the fork-like pivoted member 3' are arranged to move with respect to each other on the end faces of a tensioning device.

By means of the index bolt 1 2, the fork-like pivoted member 3' facilitates rapid coarse shortening of the chain. As can be seen from Figs. 5 and 6, the index bolt 12 can be wedged in the fork-like pivoted member 3' preferably by two balls 1 7 which are under the tension of a compression spring. A compression spring 1 8 is provided for each ball 17, which spring is mounted in a spring guide 20 accessible from outside. With corresponding counter-pressure, the balls 1 7 are deflected in the direction of the spring guide 20 and thus release the openings for introducing the index bolt 12, which openings are arranged in alignment for receiving the index bolt 1 2 in the parallel sides of the fork-like pivoted members 3'. If the counter-pressure acting on the balls 1 7 ceases or is reduced, then the balls 17 are pushed with a part of their surface out of the spring guide 20 by the compression spring 1 8. This part of the balls 1 7 which is pushed out, engages in corresponding recesses provided in the bolt 1 2. A ball 17, which is under the tension of a compression spring, is appropriately provided in each side of the fork-like pivoted member 3', so that the bolt 1 2 is reliably prevented from falling out unintentionally. Due to appropriate traction on the bolt 12, the balls 1 7 are pushed back in the direction of the spring guide 20. In this case, the traction acting on the bolt 1 2 must be greater than the spring force.

The spring guide 20 is advantageously inclined by an angle of 45 with respect to the axis of the index bolt 1 2. For the sake of easier introduction, the diameter of the index bolt 1 2 is somewhat less than the openings provided for receiving the index bolt 12, so that a clearance 14 exists between the wall of the opening and the index bolt 12.

The tensioning device with the hand tube 10 illustrated in Figs. 1 and 2 is suitable, as aforementioned, for low pre-tensioning forces of up to 4000N. For higher pre-tensioning forces, the provision of a ratchet 23 is appropriate. As can be seen from Fig. 8, the ratchet is located centrally on the tensioning device.

For higher tensioning forces, it was previously customary to use through toggles. However, in contrast to ratchet, through toggles can only be used if sufficient space is available for rotating the tensioning device. The ratchet toggle 24 is reversible and has notches (not shown). In the case of a projecting ratchet toggle 24, there would be a danger of injury or tripping. The locking arrangement 25 serves for fixing the tension achieved.

The rapid unlocking mechanism located on one end face of the tensioning device comprises a spring-loaded contact part 25, which is free to slide in slot 29. Compression spring 26 of the contact part 25 is guided at one end on a bolt stump 27, which is attached to the end coupling member 28 of the tensioning device. On the side remote from the bolt stump 27, the spring 26 is attached in a recess in the contact part 25. Located on the other end face of the tensioning device is the aforedescribed fork-like pivoted member 3'.

Compression spring 26 biases contact part 25 into engagement with the chain link 1 6 to prevent that link being released from coupling member 28. However, when contact part 25 is moved away from the link 1 6 the coupling member 28 with the tensioning device may pivot downwardly about the chain links at the other end of the tensioning device under the tension in the chain so as to release link 1 6 from coupling member 16.

The tensioning device according to Figs. 11 and 12, has two spindles 1 3a respectively with a right and left-hand screw thread. A double nut 6a is appropriately mounted on each spindle 1 3a by means of a threaded bush 30. The double nut 6a is surrounded over part of its length by a hand tube 10a, which is connected in a non-rotary manner to the double nut 6a by way of a locking pin 1 la. In the region between the two threaded bushes 30, the two spindles 1 3a are surrounded by a tube 31, which is located between the spindles aid the double nut 6a.

The tube 31 is at a distance from the spindles 1 3a and bears on the inner wall of the double nut 6a. In the vicinity of their adjacent ends, the two spindles 1 3a are respectively provided with a guide pin 32, which engages in a slot 33 extending in the longitudinal direction of the tube 31.

By rotating the hand tube 1 0a, the double nut 6a and by way of its threaded bushes 30, the two spindles 1 3a are moved in opposite directions at the same time, whereby as a result of the guidance of the spindles by means of the guide pins 32 in the slot 33 in the tube, very uniform mutual displacement of the spindles takes place. Furthermore, as a result of the positive guidance of the spindles 1 3a in the tube 31, rotation of the spindles about their axis and thus rotation of the pivoted members arranged in a non-rotary manner on the spindles is prevented in a trouble-free manner (see Figs. 1 and 2).

Claims

1. Coupling device, in particular for clamping chains, with two coupling members for receiving chain links, which comprises a releasable locking mechanism, characterised in that the coupling members are held under tension in the closed position and at least one coupling member can be moved into a released position under the force of the attached tensioned chain.

2. Coupling device according to claim 1, characterised in that for moving the coupling members, two spindles respectively with left and right hand screw threads are mounted in a double nut.

3. Coupling device according to claims 1 and 2, characterised in that a swiveling hook serving as a coupling member and clevis spanning the suspension opening formed by the hook are provided.

4. Coupling device according to claim 3, characterised in that the hook is releasably connected by its free end to the clevis.

5. Coupling device according to claims 3 and 4, characterised by a profile of the hook such that a lever arm is formed between the pivot point of the hook and the point of engagement of the chain in the hook.

6. Coupling device according to claims 3 to 5, characterised in that the hook is located between two sides of a fork connection, which sides extend parallel to each other and project freely.

7. Coupling device according to claims 3 to 6, characterised in that the clevis is formed from two parts respectively located in the plane of the sides of the fork connection.

8. Coupling device according to claims 3 to 7, characterised in that the hook and clevis are mounted to swivel about a common pivot and when closed form a ring.

9. Coupling device according to claims 3 to 7, characterised in that the two sides of the fork connection are bent obliquely upwards and as a clevis span the suspension opening formed by the hook.

1 0. Coupling device according to claims 3 to 8, characterised in that the hook is extended beyond the pivot point and the extended part of the hook can be locked and terminates on the outer wall of the tension lock.

11. Coupling device according to claim 10, characterised in that provided for locking the extended part of the hook is a sliding sleeve mounted to move on the tension lock, which sliding sleeve is contacted by a compression spring and in the locked position of the hook is slid over the end of the extended part of the hook.

12. Coupling device according to claim 11, characterised in that the end of the extended part of the hook has a profile over which the correspondingly constructed part of the sliding sleeve can be engaged.

1 3. Coupling device according to claim 1 wherein at least one coupling member is constructed in the form of a fork and comprises two sides extending parallel to each other and projecting freely with a cross-piece connecting said sides.

14. Coupling device according to claim 1 3 characterised in that the cross-piece is formed by an index bolt, which can be wedged in the fork-like pivoted member by one or more balls which are under compressive stress, a compression spring being provided for each ball which spring is mounted in a spring guide accessible from outside.

1 5. Coupling device according to claim 14 characterised in that the spring guide is inclined at an angle of substantially 45 with respect to the axis of the index bolt.

1 6. Coupling device according to claim 14 or claim 1 5 characterised in that the diameter of the index bolt is less than the openings provided for receiving the index bolt.

1 7. Coupling device according to any one of claims 14 to 16, characterised in that a ball which is under the tension of a compression spring is provided in each side of the fork-like coupling member.

1 8. Coupling device according to claim 1 characterised in that disposed centrally of the device is a ratchet with a shortening loop which is attached at the same time.

1 9. Coupling device according to claim 18, characterised in that the ratchet toggle is reversible and comprises notches.

20. Coupling device according to claim 1 8 characterised in that associated with one pivoted member is a spring loaded contact part, which is guided to move freely in all directions.

21. Coupling device according to claim 20 characterised in that the compression spring of the contact part is guided at one side on a bolt stump and at the other side is attached in a recess in the contact part and the bolt stump is attached to the end closure plate of the tension lock.

22. Coupling device, in particular for clamping chains, with two coupling members for suspending chain links, which members are able to move relative to each other and comprise a releasable locking mechanism, according to any one of claims 1 to 21, characterised in that provided for moving the coupling member are two spindles respectively with a left and right-hand screw thread, that the spindles can be moved in opposite directions by means of a double nut and that located between the spindles and the double nut is a longitudinally slit tube for guiding the spindles.

23. Coupling device according to claim 22, characterised in that respectively located at the end of the spindles is a guide pin which is guided in the slot in the tube.

24. Coupling device according to claim 22 or 23 characterised in that the nut is mounted by threaded bushes on the spindles.

25. Coupling device substantially as here it before described with reference to and as illustrated in Figs. 1, 2, 5 and 6 or Figs. 3 and 4 of Figs. 7 to 10 or Figs. 11 and 12.