GB2462495A - A coupling with deformable sections - Google Patents

Abstract

An industrial coupling A comprises tubular end sections B and a centre section C linked by two deforming sections D. Initially the coupling is seated at both ends in holes E, H that face each other at a predetermined gap G. A load (K, figure 2) is applied to the ends of the coupling that compresses both deforming sections into contact within the holes; the coupling's length continues to reduce until the gap is closed when the two parts F and J abut, thus creating an assembly. The gap preferably controls the amount of deformation and expansion of the coupling and may be established by the initial length L of the coupling minus the sum of the depths of the two holes provided in the parts to be joined together. The deforming sections preferably expand as they are compressed by an end load.

Description

COUPLING

This invention relates to a coupling device for use in Industrial Assembly, Furniture Manufacture and Building Construction.

Bolts, screws and rivets are often used in light assemblies and in buildings where their load holding capabilities and weight are greater than the application requires.

Dowels are used to locate and position parts of an assembly or construction but the parts may still be required to be held positively in contact with screws or glue.

The method used for joining parts together often needs to be concealed from view for appearance or for security purposes.

The object of this invention is to provide a lightweight replacement for bolts, screws and rivets with a tubular coupling that deforms to hold two parts together when activated.

The coupling locates as a normal dowel but additionally will hold two parts together.

The coupling is encased within the parts, thus concealed from view after the assembly.

According to the present invention there is provided an industrial coupling composed of common tubular end sections and a centre section, linked by two deforming sections.

The coupling is seated at both ends in holes produced in two parts that face each other at a pre-determined gap which is controlled by the length of the coupling; a load is then applied to the ends of the coupling that compresses and expands both of the deforming sections into a forced holding contact within the holes; the couplings length continues to reduce until the gap is finally closed when the two parts abut, thus creating an assembly.

The pre-determined gap controls the amount of deformation and expansion of the coupling and is established by the initial length of the coupling minus the sum of the depths of the two holes provided in the parts to be joined together.

The coupling's two deforming sections are created within the tubular walls by press-forming to provide a configuration that is devised to expand as it is compressed.

The two parts to be joined together can both be components of an assembly or one part can be of a solid material and the other a movable component part. Dependent upon the parts material hardness, a coupling will penetrate or be an interference fit in the hole.

Through holes in parts can be accommodated but the coupling ends will be visible.

Two couplings can be employed as dowels to accurately locate parts together and a multiple number of couplings can be used to increase the load holding capability.

Multiple deforming sections would increase the coupling's load holding capacity.

An industrial coupling can be produced from steel or aluminium tube, formed as required or alternatively from a pre-formed strip that is subsequently rolled into a tubular shape.

A plastic version could be produced to function as an industrial coupling as described.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which:-Figure 1 shows the location of a tubular coupling in two parts prior to activation.

Figure 2 shows the tubular coupling joining the parts together after activation.

Figure 3 shows one end of a coupling with optional deforming features.

Figure 4 shows a part view with further optional deforming features.

Figure 5 shows an optional feature that increases outward expansion.

Figure 6 shows one end of a coupling with an extended section with serrations added.

Figure 7 shows a part view of Fig.6 to illustrate weakening slots in the extended section.

Figure 8 shows the coupling in Fig.6 after activation.

Figure 1 shows the principal features and positioning of an industrial tubular coupling A, which comprises of a common cylindrical shape at the coupling's two end sections B and at a central section C, linked together by two deforming sections D. The coupling A is seated in a hole of depth E provided in a part F and at the coupling's other end seated in a hole of depth H provided in a part J. The gap G, between the opposing faces of the parts F and J, is established by the initial length L of coupling A minus the hole depth E and hole depth H. Therefore G = L -(E + H).

Gap G is pre-determined to control the length reduction and deformation that is devised to occur within both sections D when coupling A is eventually activated by an end load.

The deforming sections D are required to expand as they are compressed under a load and this can be achieved in a variety of different ways. To demonstrate the principle of a deforming operation a simplified example is shown in Fig. 2.

Figure 2 shows the effect of applying a load to the tubular coupling A shown in Fig.1.

The activating load K is applied to both ends of coupling A, via part F and part J, and subsequently to the deforming sections D that contain strong, smaller diameter, load transfer sections M extending from the end sections B and load reaction sections N extending from the central section C. The smaller diameter section M and section N are connected at the base of an angular ridge section P. The load K is transferred to the base of the ridge section P and compresses its angled side walls towards each other.

The strong, small diameter sections M and N maintain their shape thus forcing the ridge section P to expand outwards into contact Q with parts F and J as the gap G is closed.

Dependent on the hardness and consistency of material used in parts F and J, the contact Q could either penetrate the surface as shown or could be a tight fit.

The central section C partially locates within parts F and J (shown in Figi) prior to the activation of coupling A to ensure the positional accuracy required when the coupling is employed as a dowel. The coupling is devised to provide a dowel that also holds parts F and J together in a linear direction, thus providing a cost saving as the conventional use of screws or glue to hold parts together is avoided.

Additional features that could be introduced to assist the deformation and expansion required within the tubular deforming section D are shown in Fig.3 to Fig.7.

The features are produced by press-forming and/or piercing within the tubular section.

Alternatively, the features are produced in a flat strip of steel or aluminium, which is then rolled into a tubular shape.

Figure 3 shows one end of the coupling A, prior to activation, with additional features that can be included, either singularly or in combination, to improve the coupling's operation and effectiveness or its manufacture.

* Weakening holes 0 added to aid deformation and reduce load required.

* Multi number of angular ridge sections p added to improve holding contact.

* Foot R added to improve the location in drilled holes.

Figure 4 shows a part view of one end of a coupling where the number of angular ridge sections P has been increased over a distance by reducing the included angle S giving an improve holding contact.

Tubular load transfer section M (see Fig.2) has been replaced with an alternative conical section T to reduce the amount of press-forming required and to aid manufacture.

Figure 5 shows a part view of one end a coupling where included angle S has been increased to provide greater expansion for the same length reduction of the coupling.

Figure 6 shows one end of a coupling U, located in part F and part J as in Fig.1.

Serrations V are provided on a tubular section W linked by two angled sections X to the ends and centre sections of the coupling U. Figure 7 shows a part view on arrow Y containing one of a number of equally spaced slots Z provided to aid the deformation and expansion of coupling U. Figure 8 shows the effect of applying a load to both ends of coupling U shown in Fig.6.

The activating load K compresses the angled sections X towards each other, forcing the serrations V, provided in tubular section W, into a holding contact with the holes in part F and part J, to create an assembly in the same manner as described in Fig.2

Claims (4)

1. CLAIMS1. An industrial coupling composed of common tubular end sections and a centre section, linked by two deforming sections. The coupling is seated at both ends in holes produced in two parts that face each other at a pre-determined gap, which is controlled by the length of the coupling; a load is then applied to the ends of the coupling that compresses and expands both of the deforming sections into a forced holding contact within the holes; the couplings length continues to reduce until the gap is finally closed when the two parts abut, thus creating an assembly.
2. 2. An industrial coupling as claimed in Claim 1 where the pre-determined gap controls the amount of deformation and expansion of the coupling and is established by the initial length of the coupling minus the sum of the depths of the two holes provided in the parts to be joined together.
3. 3. An industrial coupling as claimed in Claim I whose two deforming sections have been devised to expand as they are compressed by an applied end load.
4. 4. An industrial coupling substantially as described herein with reference to Figures 1-7 of the accompanying drawing.