EP0476812B1

EP0476812B1 - Retaining clip

Info

Publication number: EP0476812B1
Application number: EP91306685A
Authority: EP
Inventors: Michael Joseph Keating
Original assignee: HERCULES PILING Ltd
Current assignee: HERCULES PILING Ltd
Priority date: 1990-08-15
Filing date: 1991-07-23
Publication date: 1996-06-05
Anticipated expiration: 2011-07-23
Also published as: IE912425A1; NO913144D0; PT98667A; GB2248263A; EP0476812A1; ATE139000T1; GB9017876D0; DE69120009D1; NO913144L; FI913851A0; FI913851A; GB2248263B; DK0476812T3

Abstract

A retaining clip for use in holding the wires of a cage created during the process of manufacturing a reinforced concrete piling comprises a plastics planar element (10) having around an edge a radial slot (15) which receives longitudinally extending wires of the cage and retains them against the pressure of a flexible tongue (16) and a second slot (25) in the plane of the element (10) which extends through the tongue (16) and part (14) of the element (10) to receive a wire rod (9) of the cage which is transverse to the other wires (1,2,3,4,5,6,7,8) and bonds them together. The element (10) has protruberances (21) on its profile which act as spacers in a mould. <IMAGE>

Description

This invention relates to. a retaining clip and is particularly, although not exclusively, concerned with clips for use in the manufacture of reinforced piling or the like in which a first longitudinally extending member is arranged to have secured to it and at an angle thereto a second longitudinally extending member which has a bend therein. The invention also relates to other applications and structures where two longitudinal members have to be retained in relative positions and examples of these include frameworks for holding tents or covers as well as in other parts of the construction industry where steel reinforcement is used in beams and slabs, whether cast on site or precast.
In the manufacture of concrete piling a cage of reinforcing elements is set into a mould and concrete is poured into the mould to embed the reinforcing element in the concrete.
The reinforcing elements are usually longitudinal extending steel rods, known as rebars, and it is necessary for these to be correctly spaced and retained, relative to each other within the mould while the concrete is applied and sets.
A current method of making the cages comprises laying out in disposed relationship four lengths of reinforcing rods and securing these relative to each other in a square or rectangular formation by winding a further rod helically around their outside. The rod that is wound around the outside is conveniently preformed as a coil of a square cross-section and is drawn out along and over the reinforcing rods to lay along their length to form a cage. It is then necessary for the helical rod to be secured to the longitudinal rods and this has been done by the simple expedient of twisting pieces of wire at the junctions of the rod and the helical rod so that the rods are held in the correct spaced relationship. The helical rod crosses the reinforcing rod at an angle which is usually of the order of between 50° and 75° to the reinforcing rod.
Sometimes it is necessary also for the reinforcing rods to comprise not only one length of rod but two lengths of rod parallelly arranged and adjacent to each other so that a cage would be made up of pairs of rods in each corner. It is also necessary when this construction is adopted to tie the rods together and to tie them with the helical rod and the wire tie system can be used for this purpose.
It is a tedious and time-consuming business to use wire for the ties as separate lengths of wire have to be cut and applied and manually twisted at each point that a tie is to be made. Attempts have therefore been made to provide a device which reduces the need for a tie. Once such device that has been proposed is a plastic clip in which two sprung arms, similar to a dolly clothes peg, are forced apart as they are inserted over the two parallel lengths of rod and the resilience in the arms is sufficient to hold the rods relative to each other. Such a clip cannot conveniently be used on the helical rod but in order to prevent the helical rod moving too far and slipping along the longitudinal rods, the clip can be positioned adjacent the correct position for the helical rod. If necessary a second clip can be provided on the other side of the helical rod. This completely limits the movement of the helical rod.
In the manufacture of concrete piling, as described above, it is necessary when placing the cage in the mould, also to ensure that it is correctly positioned in the mould which generally means that it is central of the mould and that one side of the cage is not closer to one edge of the mould than another. If this is the case then there is a risk that concrete will not cover the reinforcing rods to a sufficient degree and there may be an ingress of water through the thin concrete covering which will cause the rods eventually to rust and to flake the concrete off the cage.
DE-U-8910691 describes a spacer which is designed to receiver perpendicularly extending rods. The spacer defines first and second slots or channels. A first channel is defined by a base and side walls and receives one of the rods. The upper part of the side walls are formed to define a slot for receiving the other rod which can be retained by a flexible tongue.
It is an object of the present invention to provide a novel form of retaining clip which is suitable for use, particularly in the manufacture of piling, and which enables the elements of a cage of reinforcing rods to be correctly positioned one to the other and also to provide means for enabling the cage to be properly spaced within a mould.
According to one aspect of the present invention there is provided a retaining clip in or for use in the manufacture of reinforced piling or the like in which a first longitudinally extending member is arranged to have secured to it, and at an angle thereto, a second longitudinally extending member which has a bend therein, the clip comprising a generally planar body having a perimeter portion, a first slot having a length transverse to the plane of the body, extending inwardly from said perimeter portion, said first slot being bounded on one side by a flexible tongue which in use engages and retains the first of the longitudinally extending members, and a second slot having a length generally in the plane of the body and extending through said tongue, characterised in that said first slot is bounded on another side by a fixed wall portion which also forms a first part of the base of the second slot, said second slot including a second base part extending at an angle to said first part to define a bend in the length of the second slot, whereby said second slot can receive said second longitudinally extending member with the bend.
The body is preferably of a generally circular or part circular configuration, although it may be, in special applications, of a generally rectangular form.
The body is preferably constructed of an inert flexible plastics material such, for example, as polyethylene.
The second slot may be only in the flexible tongue and in that part of the body from which the tongue depends.
Conveniently, the inner surface of the inwardly directed first slot is provided with a groove over part or all of its surface to receive the said second member.
The perimeter of the body is preferably provided with a plurality of spacer members projecting in the plane of the element and these may be formed by a series of protuberances which may be radial in direction.
Preferably where the clip is to be used in the manufacture of a cage for making concrete piling, apertures may be formed in the body so that the clips are properly embedded in the piling when it is manufactured.
Conveniently the inwardly directed first slot is of such a depth that it may accommodate a plurality of first longitudinally extending members side by side and retain them in the slot under the action of the flexible tongue. To assist with this the wall portion of the inwardly directed slot may include retaining projections over which the longitudinally extending members ride in insertion and against which they are held by the action of the flexible tongue. Recesses or similar projections may also be carried on the face of the tongue abutting, in use, the longitudinal members.
In order to maintain the planar element as a relatively rigid element, the exterior thereof may be provided with stiffening ribs. The element may conveniently be manufactured by a moulding technique.
According to a second aspect of the invention a method of retaining two longitudinal elements at an angle relative to each other comprises locating the element in the desired relative positions and applying a clip member according to said one aspect, such that the first member engages in the slot and is retained therein by the flexible tongue and said tongue and the part of the body having the second slot in the plane of the body in which the said second member engages and is positioned below the first member in the body and is held by a clipping action in the device by the action of the tongue.
According to a third aspect of the invention, a method of manufacturing a reinforced piling comprises steps of positioning a plurality of parallel longitudinally extending spaced members in an array, winding a spiral reinforcing rod around the said spaced members, securing the rod to selected of the members with a retaining clip according to said one aspect wherein part of the spiral reinforcing rod is inserted into the said second slot in a position such that the spiral reinforcing rod is located under the first longitudinally extending member and is held firmly in the clip against the said first longitudinally extending member by the action of the flexible tongue.
A second parallel longitudinally extending member may also be included within the first slot and be held by the flexible tongue, in such a case the body may be provided with projections for locating the individual longitudinal members.
The planar member may be provided with a groove in which the spiral rod is located. The groove would lie in the plane of the element.
In order that the invention may be readily understood, one example of a retaining clip in accordance therewith and its application and the method by which it is to be applied will now be explained with reference to the four Figures of the accompanying drawings. In the Figures :

Figure 1 shows part of a cage of reinforcing members to be used in the manufacture of a reinforced concrete pile.
Figure 2 shows a side view of a clip in accordance with the invention and
Figures 3 and 4 show end views of the clip of Figure 2 in the direction of A and B respectively.

Referring now to the drawings and particularly to Figure 1, this shows a section of a cage being made up to reinforce a concrete piling. The cage is of a generally rectangle form and comprises at the corners pairs of longitudinally extending members 1; 2; 3; 4; ,5; 6; 7; 8. In manufacture these are laid out on support rollers and a coil of reinforcing rod 9 is pulled out from a stock over the outside of the rods 1 to 8. The internal dimension of the coil of the rod 9 is such that it passes over the rods 1 to 8 and the ends of the coil are secured so that the coil has a helical appearance.
It is necessary for the pairs of rods to be secured together and for the tie rod 9 to be connected intermittently to the pairs of rods. The individual coils of the rod 9 also need to be arranged so that they are substantially equally spaced along the length of the cage.
The securing is achieved by the use of a clip 10 shown schematically in Figure 1. The clip according to the invention is shown in Figures 2, 3 and 4, to which reference is now made. The clip comprises a generally planar element 10 which in this example is of a generally circular form and is moulded from a resilient polyethylene material. The element 10 comprises a perimeter rib 11 connected to a central moulding part 12 by a series of spokes 13. An upstanding section 14 is moulded to the central part 12 and this defines with one of the spokes 13 a first inwardly directed slot 15. From the top of the upstanding section 14 an inwardly directed flexible tongue 16 projects towards the centre of the element 10.
It will be seen particularly from Figure 2 that while the tongue 16 of the upstanding section 14 defines one wall of the first slot 15 part of a spoke 13 defines the other wall. The other wall is indicated at 17. Both walls have a central groove 18 in them. This groove 18 will accommodate the rod 9.
Both the upstanding section 14 and the flexible tongue 16 have a second slot 25 formed in them. This slot lies in the plane of the element 10 and is more clearly seen from Figure 3, in which the spoke 13 defining the other wall 17 of the first slot 15 is not illustrated. Thus the section 14 and the tongue 16 have a fork like appearance.
The tongue itself projects at an angle from the top of the section 14 and its free end which is directed to the centre of the planar element 10 and, as can be seen from Figure 2, the active profile i.e. the profile towards the slot 15 of the tongue is not flat but is recessed as at 19. A projection or protuberance 20 is included on the wall 18 for retention purposes.
The perimeter rib 11 has a plurality of external projections 21 which are used as spacing projections when the cage is placed in a mould for producing a piling.
In order to strengthen the spokes 13 selected ones of these spokes are tapered.
In operation the clip of Figures 2, 3 and 4 is placed, for example, as shown in dotted lines in Figure 1, over a junction between a pair of reinforcing members 7, 8 and the rod 9. The rod 9 which is bent at a right-angle at this point is settled into the groove 18 of the arm 17. To achieve this position, the rod 9 will have passed through the second slot 25. As the clip is pressed onto the cage the member 8 will be forced into the slot 15 and the flexible tongue 16 will deflect to allow the member 8 to take up the position as shown in Figure 2 where it will be engaged by the bottom of the tongue and the member 7 to be engaged above it being held by the tongue 16 and the wall recess 19.
In Figure 2 the members 7 and 8 are only showed dotted to indicate their positions and the tongue 16 is shown in its relaxed position. When the members 7 and 8 are actually in position tongue 16 will be deflected to the left in the drawing to accommodate them. The lower rod 8 in the slot 15 will be also retained by the protuberance 20 and the other rod 7 will be retained by the recessed part 19 of the tongue 16.
Since the tongue 16 is flexible and resilient it will be forcing the rods against the wall 17 and will hold them carefully and firmly in position and will also trap the winding rod 9 so that the whole configuration of the members 7, 8 and the rod 9 is maintained at the correct relative angle.
The clip is easy to fix merely by placing it in the correct position and tapping it with a mallet. This causes the flexible tongue to flex sufficiently to pass over the members 7,8 with the rod 9 slipping through the second slot 25.
In manufacturing the cage the clips are not placed at every junction between the rod and the elongate members. They are selectively placed around the cage so as to provide a sufficiently firm gripping of the cage parts so that they are held correctly and relatively rigidly.
When the cage is assembled, it is lifted and placed in a mould which is basically a trough. The projections 21 space the reinforcing members 1 to 8 and the rod 9 in the correct position relative to the walls of the trough and concrete is able to be poured into the trough to fill the spaces between the reinforcing members and also to pass between the spokes 13 of the element 10 to ensure that there is a continuity of the structure of the pile and that the clips of the invention do not have any deleterious effect on the structure.
It can thus be seen that the clip according to the invention enables the various parts of the cage to be held together in a simple yet effective manner and, since the clip itself is made of a single moulding of plastics material, it is cheap to manufacture. The application is easy, requiring no special tools and there is no wastage of material such as with the wire tying method previously used.
The invention may be varied depending on the type of cage or other construction in which the longitudinal elements are being joined. If the rod 9 was bent to other angles, the slot 9 and wall 17 would be modified in position accordingly.
Although the invention is described with respect to making the cage for reinforcing a piling,it will be appreciated that the clip can be used in many applications where longitudinal members have to be held together at selected angles.

Claims

A retaining clip in or for use in the manufacture of reinforced piling or the like in which a first longitudinally extending member (7, 8) is arranged to have secured to it, and at an angle thereto, a second longitudinally extending member (9) which has a bend therein, the clip comprising a generally planar body (10) having a perimeter portion (11), a first slot (15) having a length transverse to the plane of the body (10), extending inwardly from said perimeter portion (11), said first slot being bounded on one side by a flexible tongue (16) which in use engages and retains the first (7, 8) of the longitudinally extending members, and a second slot (25) having a length generally in the plane of the body and extending through said tongue, characterised in that said first slot (15) is bounded on another side by a fixed wall portion (17) which also forms a first part of the base of the second slot (25), said second slot including a second base part extending at an angle to said first part to define a bend in the length of the second slot, whereby said second slot (25) can receive said second longitudinally extending member (9) with the bend.
A retaining clip as claimed in claim 1 wherein said base parts of the second slot are adapted to receive and retain a second member having a bend of substantially 90°.
A clip as claimed in claim 1 or 2 characterized in that the body (10) is of a generally circular or part circular configuration.
A clip as claimed in claim 1 or 2 characterized in that the body (10) is of a generally rectangular form.
A clip as claimed in any preceding claim characterized in that the body (10) is constructed of an inert flexible plastics material.
A clip as claimed in claim 5 characterised in that the material is polyethylene.
A clip as claimed in any preceding claim characterized in that the second slot (25) is only in the flexible tongue (16) and in that part (14) of the body (10) from which the tongue (16) depends.
A clip as claimed in any preceding claim inwardly directed first slot (15) is provided with a groove (18) over part or all of its surface to receive the said second member (9).
A clip as claimed in any preceding claim characterized in that the perimeter of the body (10) is provided with a plurality of spacer members (21) projecting in the plane of the element and these members are formed by a series of protuberances which are radial in direction.
A clip as claimed in any preceding claim characterized by including apertures defined by spokes (13) in the body (10).
A clip as claimed in any preceding claim characterized in that the wall portion (17) of the first inwardly directed slot (15) includes retaining projections (20) over which the longitudinally extending members (1,2,3,4,5,6,7,8) may ride in insertion and against which they may be held by the action of the flexible tongue (16).
A clip as claimed in Claim 11, characterized in that recesses (19) are carried on the face of the tongue (16) abutting, in use, the longitudinal members (1,2,3,4,5,6,7,8).
A clip as claimed in any preceding claim characterized in that in order to maintain the body (10) as a relatively rigid element, the exterior thereof is provided with stiffening ribs or spokes (13).
A method of retaining two longitudinal elements (7,8)(9) at an angle relative to each other comprising locating the elements (7,8)(9) in the desired relative positions and applying a clip member as claimed in any preceding claim characterized in that the first member (8) engages in the first slot (15) and is retained therein by the flexible tongue (16) and said tongue (16) and the part of the body having the second slot (25) in the plane of the body in which the said second member (9) engages and is positioned below the first member (8) in the body and is held by a clipping action by the action of the tongue (16).
A method of manufacturing a reinforced piling comprising steps of positioning a plurality of parallel longitudinally extending spaced members (1, 2, 3, 4, 5, 6, 7, 8) in an array, winding a spiral reinforcing rod (9) around the said spaced members, securing the rod to selected of the members with a retaining clip as claimed in any one of claims 1 to 12, characterized in that part of the spiral reinforcing rod (9) is inserted into the said second slot (25) in a position such that the spiral reinforcing rod (9) is located under the first longitudinally extending member (8) and is held firmly in the clip against the said first longitudinally extending member (8) by the action of the flexible tongue (16).
A method according to Claim 15 characterized in that a second parallel longitudinally extending member (7) is also included within the first slot (15) and is held by the flexible tongue (16), the body (10) being provided with projections (20) for locating the individual longitudinal members (7,8).
A method as claimed in Claims 16 or 17 when dependent on Claim 8 or any claim depending therefrom characterized in that the spiral rod (9) is located in the groove (18) in the plane of the body.