GB2184050A

GB2184050A - Detachable connection between cylindrical parts

Info

Publication number: GB2184050A
Application number: GB08626577A
Authority: GB
Inventors: Werner Baranek
Original assignee: O&K Orenstein and Koppel GmbH
Current assignee: CNH Industrial Baumaschinen GmbH
Priority date: 1985-11-08
Filing date: 1986-11-06
Publication date: 1987-06-17
Also published as: FR2589959A1; DE3539612C1; IT8648499A0; GB8626577D0; JPS62113904A; IT1196648B

Abstract

A detachable connection comprises a cylindrical part (3) secured in a cylindrical bore (4) in a part (1) by the use of an expander pulling bolt (6) which is introduced into a cylindrical recess (5, 20) in the part (3) to expand the latter. The bolt (6) comprises a pressure region (7) of relatively larger, constant diameter and a guide region (8) of relatively smaller diameter, compared with the diameter of the recess (5, 20) and also a conical expander region (9) joining the pressure and guide regions. The arrangement is used in securing adjacent end members (22, Fig. 6) of a traction chain of an excavating vehicle; securing a threaded axle in a seat; and securing an axle in a train wheel hub. Bolt (6) is inserted in the recess, region 8 first, by a pressing tool, or by hammering. Bolt 6 is pushed out of the recess by a socket tool inserted through a hole (10) in bolt (6) to engage a socket (18) in a screw (15) to displace the screw (15) towards bolt (6) to press on its guide region (8). <IMAGE>

Description

SPECIFICATION Arrangement for the detachable fastening of a connection between convex- and concave-shaped parts The present invention relates to an arrangement for detachably-securing a connection between concave- and convex-shaped parts.

Such an arrangement can be used, for example, for securing an axle in a wheel or for securing adjacent members of the traction chain of a tracked vehicle.

In the context of a traction chain for a tracked vehicle, the use of a hollow end pin for securing adjacent members of the chain has already been disclosed (DE-OS 28 1,8 381). In this arrangement, a tube slotted in a longitudinal direction has a conical socket at each end, in which there is an externallythreaded cone which is pulled inwards by being screwed into the conical socket and thus enlarges the external diameter of the tube, as a result of which the hollow end pin is tightened in the chain links.

Such a hollow end pin suffers from the disadvantage that the thread on the cone can be destroyed before a pressing force sufficient to secure the connection between the adjacent track chain members has been reached.

In addition, an arrangement has been disclosed (DE-OS 34 32 074) for connecting adjacent members of a heavy-duty traction chain by means of an end link pin which, when introduced, sits lightly in the eyes of the link plates of the adjacent members. An interference fit for the pin in the eyes of the outer link-plates (brought about by an adjustable flexible increase in the diameter of the pin) is produced by pulling an unthreaded cone into a conical bore at each end face of the pin.

A disadvantage of such an arrangement is that, in practice, only parts of the cone surface are effective in fastening the mechanical connection. As a result it is difficult to achieve adequate pressing forces without destroying the material.

The present invention provides an arrangement for securing the connection between concave- and convex-shaped parts, in which the convex-shaped part has a recess which is cylindrical at least in the region in which the connection is to be secured and into which an expander component can be introduced, which component has a pressure region of relatively larger, constant diameter and a guide region of relatively smaller diameter, compared with the diameter of the said cylindrical part of the recess, and also a conical expander region joining the pressure and guide regions.

The expander component may have a bore along its whole length.

The recess in the convex-shaped part may be threaded over a part of its length outside the said securing region. This threaded region may be closed by a screw, the diameter of which is preferably greater than the diameter of the bore in the expander component. The expander component is then removable from the recess by longitudinal displacement of the screw, the latter being engageable by a tool inserted through the bore in the expander component.

This invention provides, more especially, an arrangement for securing the connection effected, between adjacent members of a traction chain, by a link pin which is a snug fit in the eyes of the link plates of the adjacent members, the arrangement comprising an expander component which is introduced into a recess in the link pin, the expander component comprising a pressure region of relatively larger, constant diameter and a guide region of relatively smaller diameter, compared with the diameter of the recess in the region of the connection, and also a conical expander region joining the pressure and guide regions.

By way of example, embodiments of the invention will now be described with reference to the accompanying drawings in which: Fig. 1 shows an arrangement in accordance with the invention; Figs. 2 to 5 show details of the arrangement of Fig. 1, and Fig. 6 illustrates an application of the arrangement of Fig. 1.

Fig. 1 shows a basic arrangement for the detachable fastening of a mechanical connection between a first component 1 having a concave-shaped part 2 and a second component 3 having a convex-shaped part 4. As shown, both shaped parts are of cylindrical design so that the concave-shaped part 2 provides a bore in the first component 1. The convex-shaped part 4 has a central recess 5 in its outer end, which can be manufactured by drilling or turning. The central recess 5 is cylindrical in shape at least in the fastening region of the two components 1 and 3. Introduced into the recess 5 is an expanding pulling bolt 6 which has a pressure region 7, a guide region 8 and, joining these two regions, a conical expander region 9.

It can also be seen from the drawing that the pulling bolt 6 has, over its entire length, a central drilled hole 10 which is provided with a thread 11 at its outer end. As a result the drilled hole 10 can be closed off by a threaded plug 12 and, if desired, oil can be introduced into the drilled hole 10 and the chamber 13 adjacent the other end of the pulling bolt 6.

In the threaded plug 12 is a polygon socket 14, preferably a hexagon socket, for assembly purposes.

The drawing also shows a screw 15 screwed into a central thread 16 on the second component 3. This screw 15 is provided at least at one end 17 with a polygon socket 18. This socket is. also preferably a hexagon socket.

It will be apparent that, with the threaded plug 12 removed, the polygon socket 18 can be engaged through the drilled hole 10 in the pulling bolt 6 by a socket tool, enabling the screw 15 to be longitudinally displaced. The end 17 of the screw, containing the polygon socket 18, is located in a transition chamber 19 in the central recess 5, between a cylindrical chamber 20 at the outer end of the recess and the central thread 16.

The removal of the pulling bolt 6 from the second component 3 is carried out in the following way. The threaded plug 12 is removed so that the drilled hole 10 in the pulling bolt 6 is free, and a socket tool is then introduced and used to unscrew the screw 15 in the direction towards the pulling bolt. The head diameter of the screw 15 is required to be greater than the diameter of the drilled hole 10 so that, after a few turns, its front end presses against the end surface of the guide region 8 of the pulling bolt 6 and pushes the latter out.

Fig. 2 is an individual representation of the second component 3. The central recess 5 is of varying shape over the length of the second component 3 and substantially comprises the cylindrical chamber 20, the transition chamber 19 and the portion having the central thread 16.

Fig. 3 shows the pulling bolt 6 as an individual element. At its periphery it comprises the pressure region 7, the guide region 8, and the conical expander region 9 joining these two regions. The pressure region 7 has a relatively large diameter and the guide region 8 a relatively small diameter, compared with the diameter of the cylindrical chamber 20 in the second component 3. The conical expander region 9 is shaped to provide the connection between the two different diameters of the adjacent regions 7 and 8.

Also to be seen in Fig. 3 is the drilled hole 10, including the part provided with the thread 11.

For the purpose of fastening the connection between the first component 1 and the second component 3 the pulling bolt 6 is introduced into the central recess 5 by means of a suitable pressing tool (not shown) which is known per se. The guide region 8, which is relatively small in diameter compared with the diameter of the cylindrical chamber 20, allows easy introduction and centering of the pulling bolt 6. As the bolt is pressed in, the expander region 9 widens the cylindrical chamber 20 until it reaches the diameter of the pressure region 7. At the same time smoothing and compacting of the wall material takes place.

Lubricants known per se facilitate the introduction of the bolt. As a result, the pressingin of the bolt 6 (using the entire surface of the constant diameter pressure region 7) causes the convex-shaped part 4 of the component 3 to be widened and pressed against the concave-shaped part 2 of component 1. It is essential for ensuring the fastening of the connection that the pressing surfaces can be precisely selected and defined, and it has been found that the provision of the conical expander region 9 allows the pressing-in -operation to be carried out with surprisingly low pressing-in forces. Easy to handle tools that can be carried about for assembly purposes are sufficient.

An advantage of the arrangement shown in Fig. 1 is that, because high pressing forces can be achieved, the wall thickness in the component 3 around the cylindrical chamber 20 can be large and, as a result, it can be ensured that any shearing forces acting on the mechanical connection cannot lead to the destruction of the component.

Fig. 4 shows, as an individual element, the plug 12 with its polygon socket 14 and the thread 11 on the outer surface.

Fig. 5 illustrates the screw 15 with the thread on its outer surface over its entire length and with a polygon socket 18 at least at one end.

The basic arrangement according to Fig. 1, with its individual elements as shown in Figs.

2 to 5, can find quite general application. For example, the first component 1 might be the hub of a wheel, especially a train wheel, and the second component 3 would then be the wheel axle. In this case, the arrangement has the great advantage that placing the wheel on the axle is very easy and any damage to the wheel axle is avoided. The fastening of the two parts then takes place separately, without friction between them, during the pressing operation when the bolt 6 is inserted. The pressing forces required for this are also considerably smaller than in the previously known method of putting a wheel onto an axle, for which stationary presses are required. A further advantage of using the arrangement illustrated in Fig 1 is seen especially when the wheel-sets of rail vehicles have to be disman styled again for reworking of the running surfaces. The damage occasioned in the dismantling-the pulling-off of the wheel from the axle-is also avoided.

The basic arrangement shown in Fig. 1 can also be used when the component 1 is a nut which is screwed onto and fastened to a threaded axle (component 3). When, in such an arrangement, the pulling bolt 6 is removed, the contraction of the surrounding portion of the threaded axle (corresponding to the component 3) causes it to break itself loose in the individual turns of the thread. The nut (corresponding to the component 1) can therefore be removed again easily. An extension may be provided on the pulling bolt 6 in the direction away from the guide region 8, the extension being used for pressing the bolt in by hammering and as a working surface for tools, for example pliers, for removing the bolt (for example, in the absence of the screw 15).

A development of the apparatus according to the invention is that the pressure region 7 of the pulling bolt 6 is made longer than the pressing region of the convex-shaped part 4.

The latter will then curve out or bulge in the region just outside the component 1, either on one side or on both sides according to the nature of the enlargement caused by the pressure region 7 with the result that the first component 1 is prevented, by the change in shape, from being displaced in the axial direction of the second component 3.

The simplest form of mechanical connection using the arrangement of Fig. 1 is produced by a plug-in connection between the first component 1 and the second component 3, although a connection can also be made by changing the shape of the contact surface of the second component 3 as just explained, for example, or by using a screw connection.

Fig. 6 shows a preferred embodiment of the invention for reliable connection and detachment of adjacent end members of the traction chain of a tracklaying vehicle. The end pin 21 is detachable but can be connected securely to the outer link-plate eyes 22. The inner link plates 24 rest on the inner plate sleeve 23.

The pulling bolt 6 and the use of an arrangement as described above, allow the technical requirements to be guaranteed easily, even with the large linkages of heavy excavating vehicles.

Since a reliable connection with the end pin 21 has to be produced at two places in such an arrangement because there are two outer link-plate eyes 22, two pulling bolts 6 are also used (one at each end of the pin 21). 6 In such a case it is advantageous to provide a polygon socket 18 at each end face of the set screw 15 so that the pulling bolt 6 can be removed at either side of the chain, as only one side may be accessible. Alternatively, if both sides of the chain are accessible, socket tools can be used in both polygon sockets 18 for removing the pulling bolt.

An arrangement of the type shown in Fig. 1 is not restricted to the uses described above but can be used anywhere where detachable connections are to be fastened, simple developments being within the scope of the user.

For example, in the case of some structural shapes, the length of the pressure region of the pulling bolt 6 and of the pressing region of the concave-shaped article 2 can be varied.

The important point in each case is that the holding strength of the connection should remain greater than the maximum occurring force capable of breaking up the connection.

The securing arrangements described above offer the advantage that, because of the shaping of the expander component (bolt 6), only comparatively small pressing forces are required for introducing and detaching the expander component and furthermore reliable securing and subsequent release of the mechanical connection can be ensured through selection of the pressure and pressing surfaces (such as the surface of the pressure region 7 of the expander component).

Claims

1. An arrangement for securing the connection between concave- and convex-shaped parts, in which the convex-shaped part has a recess which is cylindrical at least in the region in which the connection is to be secured and into which an expander component can be introduced, which component has a pressure region of relatively larger,constant diameter and a guide region of relatively smaller diameter, compared with the diameter of the said cylindrical part of the recess, and also a conical expander region joining the pressure and guide regions.

2. An arrangement according to claim 1, in which the expander component has a bore along its whole length.

3. An arrangement according to claim 2, in which part of the bore has a thread.

4. An arrangement according to claim 3, in which an end of the thread is located at an outer end wall of the pressure region of the expander component.

5. An arrangement according to claim 4, in which the bore is closed-off by a threaded plug.

6. An arrangement according to claim 5, in which the threaded plug has a polygon socket in its head.

7. An arrangement according to claim 6, in which the socket is a hexagon socket.

8. An arrangement according to any one of the preceding claims, in which the recess in the convex-shaped part is threaded over a part of its length outside the securing region.

9. An arrangement according to claim 8, in which the threaded region of the recess is closed by a screw.

10. An arrangement according to claim 9 when appendant to claim 2, in which the diameter of the screw is greater than the diameter of the bore in the expander component.

11. An arrangement according to claim 10, in which the screw has a polygon socket in its head.

12. An arrangement according to claim 11, in which the socket is a hexagon socket.

13. An arrangement according to claim 11 or claim 12, in which the socket in the head of the screw is engageable, through the bore in the expander component, by a socket tool for displacing the screw longitudinally.

14. An arrangement according to any one of claims 8 to 13, in which a transition chamber is provided in the recess in the convexshaped part, between the cylindrical and threaded parts of the length of the recess.

15. An arrangement according to any one of the preceding claims, in which the expander component can be introduced by a pressing tool into the recess, beginning with the guide region.

16. An arrangement according to claim 9, in which the expander component is removable from the recess by longitudinal displacement of the screw.

17. An arrangement according to any one of the preceding claims, in which the location in the recess of the pressure region of the expander component approximately coincides with the region of engagement between the convex and concave-shaped parts.

18. An arrangement according to claim 17, which is modified in that the pressure region extends, at least on one side, beyond the region of engagement.

19. An arrangement according to any one of the preceding claims, in which the connection between the shaped parts is a plug-in connection.

20. An arrangement according to any one of claims 1 to 18, in which the connection between the shaped parts is a screw connection.

21. An arrangement for securing the connection effected, between adjacent members of a traction chain, by a link pin which is a snug fit in the eyes of the link plates of the adjacent members, the arrangement comprising an expander component which is introduced into a recess in the link pin, the expander component comprising a pressure region of relatively larger, constant diameter and a guide region of relatively smaller diameter, compared with the diameter of the recess in the region of the connection, and also a conical expander region joining the pressure and guide regions.

22. A method of securing a connection by an arrangement as claimed in claim 1, in which the expander component is pressed into the recess, guide region first.

23. A method of releasing a connection which is secured by an arrangement as claimed in any one of claims 10 to 13, in which the screw is displaced longitudinally to push the expander component out of the recess.

24. A method as claimed in claim 23, in which the screw is displaced longitudinally by a tool inserted through the bore in the expander component to engage the screw.

25. A method as claimed in any one of claims 22 to 24, substantially as described herein.

26. An arrangement for securing a connection, substantially as described herein with reference to, and as shown in, Figs. 1 to 5 of the accompanying drawings.

27. An arrangement for securing a connection between adjacent members of a traction chain, the arrangement being substantially as described herein with reference to, and as shown in, Fig. 6 of the accompanying drawings.