Connector device assembly

Abstract: A connector device assembly of the add-on type and suitable for securing a second member, such as a metal tube, or branch (14) extending from a position between the ends of a first member (15), such as another metal tube, without the need to slide components along the first member comprises two connector devices (20) each having a first body region (23) which defines a recess formation (24) to accommodate a first member of a structural assembly, and at least one of the connector devices comprising a second body (22) region for securing a second member which is required to be connected to the structural assembly, said two connector devices (20) each having at least one edge formation provided with an aperture (27) which extends substantially parallel with the longitudinal direction of said first member and respective edge formations of said two connector devices being aligned in the assembly to receive a locking member (40) extending therethrough, the locking member being arranged in the assembly to be loaded substantially only in shear to hold the connector devices (20) in position relative to one another and the first member.

Description: The present invention relates to a connector device assembly, and a method, for forming a structural interconnection between two rigid members. More specifically, the invention relates to a connector device assembly of an "add on" type, sometimes known as a split type connector device assembly, which allows an existing structural assembly of interconnected members to be extended or modified without the need to dismantle any part of the existing assembly. The structural assembly with which the connector device assembly of the present invention may be used to advantage, and to which the method may be applied, may be of the type comprising rods or tubes interconnected by multi-way connector pieces for joining two or more lengths of said rods or tubes. One or more pairs of said "lengths" typically may each be aligned sections of a continuous length of rod or tube. Additionally or alternatively the assembly may comprise one or more lengths of a rod or tube having an end which terminates at the connector piece. Examples of structural assemblies to which the present invention relates include handrails, balustrades, shelving and storage systems, climbing frames and scaffolding. 'Add-on' devices of various types are known for allowing additional rods or tubes to be connected to an existing structural assembly of rods or tubes without the need to dismantle any part of the existing assembly. A particularly commonly used and simple type of an add-on connector device assembly comprises a pair of semi-cylindrical connector pieces which, in combination, can encircle a rod or tube, and which are held together by retention nuts acting on bolts which extend through aligned, drilled and tapped apertures in the connector pieces. Either the bolts may extend in a generally tangential direction perpendicular to the longitudinal direction of the or each encircled rod or tube, as shown in US-A-4864795 (and as illustrated in Figure 1 hereof), or parallel with said longitudinal direction as described in GB-A-552105in US-A-3,737,180, or in our GB-A-2316121 (illustrated in Figures 2 to 5 hereof). Although the use of add-on type connector pieces advantageously allows a connection to be made to an existing structural assembly without the need to dismantle any part of the existing structure, the pieces often are difficult to install especially when assembling at height or at a position of extreme reach. Notably, two pairs of hands are required, one pair to hold the two connector pieces together in aligned orientation and the other pair to position retention bolts and tighten the nuts. In addition to the difficulty of forming the assembly with a single pair of hands, it can also be difficult always to ensure that a pair of the semi-cylindrical connector pieces have been properly assembled with an appropriate torque loading of the bolts. If the torque is too great there is a risk of fracture either on assembly or during subsequent service, or damage to the tapped holes. If the torque is too low, there is a risk of vibration or thermal expansion effects relaxing the interconnection of the connector pieces. An object of the present invention is the provision of a connector device assembly and a method which more easily allows additions to be made to an existing structural assembly. According to one aspect of the present invention an add-on type connector device assembly comprises two connector pieces and a lockin member, each connector piece having a first body region which defines a recess formation to accommodate a part of the outer periphery of an elongate first rigid member of a structural assembly, and at least one of the connector pieces comprising a second body region securable to a second rigid member which is required to be connected to the structural assembly, at least one of said connector pieces comprising retention means, for locking the assembled connector pieces to said first rigid member, said two connector pieces each having at least one edge formation at an edge of the recess formation, said at least one edge formation being provided with an aperture which, in use, extends substantially parallel with the longitudinal direction of said elongate first rigid member and respective edge formations of said two connector pieces being aligned in use to receive said locking member extending through the thus aligned apertures, the locking member being a tapered pin which forms an interference fit in at least one of the aligned apertures, and said retention means being operable to simultaneously lock the assembled connector pieces to said first rigid member and load the tapered pin in shear. Preferably said applied action is one which has caused the locking member to become tightly secured in at least one of the aligned apertures through which it extends. The tapered pin may be tapped into place with a hammer to form an interference fit in at least one aligned aperture of each of two connector pieces. In general a suitable tapered pin will have a taper (as measured relative to the longitudinal direction of the pin) of between 0.005 and 0.1 millimetres per centimetre, more preferably between 0.01 and 0.05 mm./cm. A taper of 0.02 mm./cm. is found to be particularly suitable. Optionally the smaller of the two taper ends of the pin extends axially outwards of an aperture thereby to facilitate drifting out of the pin if the assembly requires to be dismantled. The pin may have a head portion to limit axial movement and prevent over stressing of the parts of the connector pieces which define the apertures. The length of the pin may be less than the length of the aligned apertures. The pin may be toleranced so as normally to lie substantially wholly within said length of the apertures. In an assembly which employs tapered pins of a circular section, the pin diameter typically may have a tolerance which complies with British Standard BS 46pt3. Optionally the material of a tapered pin has a hardness which is less than that of the material which defines the apertures of the connector pieces. Whilst it is required by one aspect of the present invention that the locking means is of a kind inserted and tightened in an aperture only by action at one end of the locking means, it is to be understood that other locking means may be provided additionally and/or subsequently. Thus a captive locking device such as a star-lock push-on fastener, a "flat nut", or a latch pin may be provided at an exposed part of the other end of the tapered pin. The apertures in the edge formations of a connector piece may be bereft of a screw thread formation. The apertures may be of a smooth bore type, and may have been sized by reaming. A reamer or other means may be employed to provide a connector piece with cylindrical apertures and/or one or more tapered apertures. All or only some of the apertures which form an aligned series of apertures in an assembly of two or more connector pieces may be tapered. Neighbouring edge formations in use may comprise more than two aligned apertures and the locking member may be a tight fit in all or more than two aligned apertures. In an aligned series of apertures, two or more successive apertures may be tapered and arranged to provide a through - passage zone of uniformly tapering cross-section whereby a tapered pin of corresponding taper angle may be fitted securely in to each of said two or more successive apertures. If the connector pieces of an assembly are of a kind which can be interconnected relative to one another in only one configuration, it is taught that the whole length of a through-passage defined by the aligned apertures may taper uniformly. If the connector pieces of an assembly are of a kind which can be interconnected relative to one another in more than one configuration, it may be provided that in each relative configuration some but not all of the successive aligned apertures may taper uniformly. In one preferred construction two connector pieces encircle a first rigid member and each edge formation has a pair of aligned apertures which in the assembly lie interdigitated with the apertures at a neighbouring edge of the other connector piece. An example of a construction of that type and which is reversible to lie in either of two configurations is shown in figures 2 to 5 hereof. The pieces can be interconnected in either of two configurations as more fully described in GB-A-2 316 121A, and selected apertures may be tapered to ensure that in either of the configurations two, but not all, of the aligned apertures provide a through-passage zone which is uniformly tapered. Thus, each edge formation may be regarded as having an outer aperture and an inner aperture which in the assembly lies sandwiched between the outer and inner apertures of the other edge formation with which it is interdigitated. The outer apertures may taper with reducing diameter in a direction towards the associated inner aperture, and said associated inner aperture may taper in a reverse direction, i.e. reducing in diameter in a direction towards the associated outer aperture, with the taper of the inner aperture decreasing from a maximum diameter corresponding to the minimum diameter of the taper in the outer aperture so that in the assembled condition the adjacent inner and outer apertures provide a uniformly tapering through passage zone. A taper pin inserted in either end of the aligned apertures will therefore be able to fit firmly into two of the four aligned apertures through which it extends. One of the connector pieces may be provided with retention means in the form of a grub screw operable to lock the assembled connector pieces to said first rigid member. According to yet another aspect of the present invention a method of forming a structural interconnection between two rigid members comprises use of an add-on type connector device assembly which comprises two connector pieces and a locking member, each connector piece having a first body region which defines a recess formation to accommodate a part of the outer periphery of an elongate first rigid member to be connected to a second rigid member, at least one of the connector pieces comprising a second body region securable to the second rigid member, said two connector pieces each having at least one edge formation at an edge of the recess formation , said at least one edge formation being provided with an aperture which, in use, extends substantially parallel with the longitudinal direction of said elongate first rigid member, apertures of the respective edge formations of said two connector pieces being aligned in use to receive said locking member, retention means associated with one of the connector pieces and operable to secure the assembled pair of connector pieces in position relative to the first rigid member, the method further comprising providing a tapered pin to serve as said locking member, first employing the locking member to provide an interconnection of the connector pieces without creating any substantial axial pre-load between the connector pieces in said longitudinal direction and then operating the retention means simultaneously to secure the assembled connector pieces relative to the first rigid member and apply shear load to the locking member. The method is particularly suitable for use with connector pieces having two pairs of interdigitated lugs with commonly aligned apertures as disclosed in our GB-A-2316121. The aforedescribed method is particularly suitable for use in creating an assembly if the other edges of the piece are hingedly connected by a loose type hinge pin that permits non-axial relative movements. The first body region of a connector piece may comprise first and second end formations arranged spaced apart by said recess formation in a non-symmetrical manner relative to an axis that intersects the longitudinal direction of the first rigid member whereby the first end formation lies between said second body region and said second end formation. Said second end formation may be adapted to co-operate with that of the other connector piece to embrace a first rigid member and form a structural interconnection between the rigid members. The second region of the body may have a major axis which is substantially aligned relative to the length direction of at least an end portion of said second rigid member, and a plane intersecting the lengths of the first and second end formations may lie substantially obliquely relative to said major axis. The end zone of the first region preferably lies, in effect, in a plane which is parallel with, and more preferably intersects, a major axis of the first rigid member. The end zone of the first body region preferably has associated therewith a recess of substantially semi-cylindrical shape. Thus parts of the end zone at either side of the recess may lie at diametrically opposite positions of a cylindrical outer surface of a rod or tube which fits into the recess. The recess preferably comprises at least a pair of axially spaced semi-cylindrical bearing surfaces, known also as sizing rings, against which a rod or tube of substantially equivalent outer diameter may rest and be secured. An assembly of the present invention may comprise a connector piece of a type which comprises a second body region for securing relative to a second rigid member and a region having an end zone which comprises a recess formation to accommodate a part of the outer periphery of the first rigid member, the end zone additionally comprising a first end formation which lies between said second body region and a major axis of said recess formation and a second end formation which lies beyond said major axis. The major axis of said second region of the body may intersect or lie off-set relative to the major axis of the recess or the first rigid member. The end zone preferably comprises end formations which in effect lie in a plane inclined at 45 degrees to the major axis of said second region. Two connector pieces with said 45 degree feature therefore may be orientated either to provide an in-line interconnection of the two rigid members, to lie typically but not necessarily at right angles to a first rigid member contained within confronting recesses, or a right angled interconnection between said two rigid members. It is not essential to all aspects of the present invention that the aforedescribed reversibility feature is present. Thus, an end zone may lie at 90 degrees to the major axis of said second region. Other angles may be employed and still provide a reversibility feature as described in the preceding paragraph, . e.g. a 30 degree inclination to the major axis will give the option for an in-line or 60 degree interconnection. The end formations preferably are profiled and arranged, e.g. with an off-set configuration of lug portions, so that the end formations of respective connector pieces may lie interdigitated in either of two relative orientations of the pieces. Two connector pieces may be pre-assembled with a hinged interconnection of a pair of adjacent edge formations. Another pair of adjacent edges may then be fitted with a locking member arranged to extend through aligned apertures in lug formations as described herein in accordance with the present invention. All locking member apertures of the assembly may be of the same size or some may be smaller than others A structural member may be secured in conventional manner to the second body region. A structural member may be received in an end passage of a second body region. The passage may comprise a pair of axially spaced and inwardly extending ribs to act as gauge rings to closely surround an inserted rigid structural member. The end region may comprise a known boss and grub-screw arrangement for securing the structural member in the connector piece. An add-on type connector piece as aforedescribed and having a pair of apertured edge formations, such as may be provided by edge lugs, may be used either in combination with a similar connector piece or one of a different form. A different form of connector piece may feature an additional second body portion so that in combination with the aforedescribed add-on type connector piece a total of four rigid members may be added about a first rigid member which is encircled by the connector pieces. Embodiments of the invention are now described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a known connector piece; Figure 2 is a perspective view of another known connector piece, but which may be employed in the present invention; Figure 3a, 3b, and 3c are plan, end and side views of the connector piece of Figure 2; Figure 4 shows an in-line assembly of two pieces of Figure 2; Figure 5 shows a right angle assembly of two pieces of Figure 2; Figure 6 shows a locking member for use in forming the piece of Figure 3 into an assembly of the present invention; Figure 7a is a view similar to that of figure 3c of a connector piece in accordance with another embodiment of the invention, and Figure 7b shows part of an assembly of two of the connector pieces of figure 7a, in section on the axis of an aligned series of apertures. Figure 1 shows a connector assembly 10 comprising two rigid cast connector pieces 11a & 11b which define two passages 12, 13 through which tubes 14,15 extend. A side tube 16 is located in a passage 17 of the connector piece 11b. The three tubes are secured to the connector pieces by grub screws in bosses (not shown). The assembly is more fully described in US-A-4864795. The two connector pieces 11a, 11b are held together about the tubes 14, 15 by threaded bolts 9 and lock nuts 8. The integrity of the assembly is dependent on the bolts 9 being set to the correct torque to resist separation of the connector piece surfaces 7 that contact one another whilst also withstanding vibration and thermal expansion effects. Figure 2 shows in perspective a connector piece for use in forming an assembly of the present invention. The connector piece 20, shown in more detail at Figure 3a, b, and c, has a tubular body portion 21 with a central region 22 adapted to receive the end of a side tube (not shown). The body 21 has another region 23 comprising a recess formation 24 of a semi-cylindrical shape and two pairs 25, 26 of lug formations. The lug formations in effect lie on a plane A-A (see figure 3a) which is oblique, at 45 degrees, relative to the major axis 28 of the region 22. Hence one pair 26 of lug formations lies between the region 22 and a major axis 29 of the recess. The other pair 25 lies beyond the major axis 29 of the recess. The lug formations 25, 26 are arranged off-set as viewed in Figure 3c. In consequence when two of the connector pieces 20 are positioned about a tube, which occupies the recesses 24, the lug formations of the respective pairs may lie aligned and interdigitated irrespective of whether the pieces are in-line as in Figure 4 or at right angles as in Figure 5. The connector piece 20 is provided with a boss and grub screw (not shown) for retention of the side tube in a known manner. The lug formations 25, 26 are formed with apertures 27. All apertures are of the same internal diameter and have a smooth bore. Locking members, as described below, extend through aligned apertures 27 to secure the two pieces 20 to one another. Another boss and grub screw arrangement 30 (see figure 2) is provided at the recess to tighten the connector pieces relative to a tube extending through the recesses. The locking means comprises a tapered pin 40 as shown in figure 6. Optionally it may have a head portion 41 to limit excessive movement of the pin into apertures and thereby avoid excessive interference fit forces. The taper is 0.02 mm per cm relative to the longitudinal axis of the pin. Optionally the pin also has a tail portion 42 which lies slightly exposed beyond a lug 25,26 in the assembled condition whereby the pin can be drifted out from the apertures by tapping of the tail part. Figures 7a and 7b show a modification of the embodiment of figures 2 to 5 in which apertures in the lugs are tapered (tapers not shown to scale) and arranged to receive a taper pin of corresponding taper angle. Figure 7a shows that the outer lugs 95,95' have tapered apertures 97 which taper with reducing diameter in a direction towards aligned inner tugs 96, 96'. Inner tugs 96, 96' have tapered apertures 98 which taper in an opposite direction, and with reducing diameter, towards the respective aligned outer lugs 95, 95'. The maximum diameter of the apertures 98 equals the minimum diameter of the apertures 97 and hence, as shown in figure 7b, when two of the pieces of figure 7a are assembled together to form two series of aligned apertures, in each series an adjacent pair of inner and outer lugs defines a through-passage zone in which a taper pin can firmly locate.

Claims: An add-on type connector device assembly comprising two connector pieces (20) and a locking member (40), each connector piece having a first body region (23) which defines a recess formation (24) to accommodate a part of the outer periphery of an elongate first rigid member of a structural assembly, and at least one of the connector pieces comprising a second body region (22) securable to a second rigid member which is required to be connected to the structural assembly, at least one of said connector pieces comprising retention means (30), for locking the assembled connector pieces to said first rigid member, said two connector pieces (20) each having at least one edge formation (26) at an edge of the recess formation (24), said at least one edge formation being provided with an aperture (27) which, in use, extends substantially parallel with the longitudinal direction of said elongate first rigid member and respective edge formations of said two connector pieces being aligned in use to receive said locking member (40) extending through the thus aligned apertures (27), characterised in that the locking member is a tapered pin (40) which forms an interference fit in at least one of the aligned apertures (27), and said retention means (30) is operable to simultaneously lock the assembled connector pieces to said first rigid member and load the tapered pin (40) in shear. An add-on type connector device assembly according to claim 1, characterised in that said apertures (27) are bereft of a screw thread formation. An add-on type connector device assembly according to claim 1 or claim 2, characterised in that said apertures (27) are of a smooth bore type . An add-on type connector device assembly according to any one of the preceding claims, characterised in that in use the smaller of the two ends of the tapered pin (40) extends axially outwards of an aperture (27). An add-on type connector device assembly according to any one of claims 1 to 3, characterised in that in use the tapered pin (40) lies substantially wholly within the length of the aligned apertures (27). An add-on type connector device assembly according to any one of the preceding claims, characterised in that the material of the tapered pin (40) has a hardness which is less than that of the material which defines the apertures (27) of the connector pieces. An add-on type connector device assembly according to any one of the preceding claims, characterised in that the apertures (27) are cylindrical. An add-on type connector device assembly according to any one of claims 1 to 6 characterised in that neighbouring edge formations in use each comprise more than two aligned apertures (27), two or more successive aligned apertures in use are tapered and arranged to provide a through -passage zone of uniformly tapering cross-section, and the tapered pin (40) is a tight fit in at least two of said successive, aligned apertures. An add-on type connector device assembly according to any one of claims 1 to 6 characterised in that the assembly comprises two connector pieces (20) of a kind which can be interconnected relative to one another in more than one configuration, and in each relative configuration some but not all of the successive aligned apertures (97, 98) taper uniformly, each edge formation having a pair of aligned apertures (95, 96, 95', 96') which in the assembly lie interdigitated with the apertures at a neighbouring edge of the other connector piece whereby in either of the configurations two of the successive aligned apertures (97, 98) provide a through-passage zone which is uniformly tapered. Method of forming a structural interconnection between two rigid members comprising use of an add-on type connector device assembly which comprises two connector pieces (20) and a locking member (40), each connector piece having a first body region (23) which defines a recess formation (24) to accommodate a part of the outer periphery of an elongate first rigid member to be connected to a second rigid member, at least one of the connector pieces (20) comprising a second body region (22) securable to the second rigid member, said two connector pieces each having at least one edge formation (26) at an edge of the recess formation (24), said at least one edge formation being provided with an aperture (27) which, in use, extends substantially parallel with the longitudinal direction of said elongate first rigid member, apertures of the respective edge formations of said two connector pieces being aligned in use to receive said locking member (40), retention means (30) associated with one of the connector pieces and operable to secure the assembled pair of connector pieces in position relative to the first rigid member, characterised in that the method comprises providing a tapered pin to serve as said locking member (40), first employing the locking member (40) to provide an interconnection of the connector pieces without creating any substantial axial pre-load between the connector pieces in said longitudinal direction and then operating the retention means (30) simultaneously to secure the assembled connector pieces (20) relative to the first rigid member and apply shear load to the locking member (40). Method according to claim 10, characterised in that it comprises the use of a tapered pin (40) which on initial assembly is a close fit in only one of the aligned apertures (27) through which it extends. K10CEP2wps

Inventors: OVERTON MICHAEL DEREK, PRESANT CHARLES WILLIAM STRATF, OVERTON, MICHAEL DEREK, PRESANT, CHARLES WILLIAM, PRESANT, CHARLES WILLIAM STRATFORD
Applicants: KEE KLAMP LTD, KEE KLAMP LIMITED
Application year: 1999
Main classification: F16B7
IPC codes: F16B7