Patent Grant
9808854
Technical Field
The present invention concerns an apparatus for automatically twisting metal wires, in particular for connecting adjacent, preferably mutually crossing structural elements. The term structural element is used in the context of this invention to denote an elongate body of a round or polygonal, for example quadrangular cross-section. Examples of such structural elements are for example tubes, bars or carriers, as are used in many respects in all fields of industry. Stranded wire bundles, so-called stranded wire cables, or prestressing cables are also viewed as being embraced by the term structural element, being used inter alia for the production of reinforcing cages for prestressed concrete components.
Description of the Related Art
A typical area of use for apparatuses of the kind set forth in the opening part of this specification is the production of such reinforcing cages, for example for prestressed concrete elements. Reinforcing cages have a lattice-like structure comprising (steel) stranded wires. The lattice-like structure is achieved by stranded wires in a first direction and stranded wires in a second direction being arranged in mutually crossing-over relationship. In the region in which they cross each other, the so-called twisting region, the position of the stranded wires relative to each other is fixed by means of a metal wire. The metal wire is laid around the twisting region of the stranded wires, whereby a loop is formed. The two ends of the wire are then twisted relative to each other a plurality of times until the loop of the wire is sufficiently tight to fix the two mutually crossing stranded wires or generally the mutually crossing structural elements relative to each other.
Alternatively to a crossing-over arrangement of a plurality of structural elements, frequently generally adjacent structural elements are fixed by means of twisting wires around the adjacent structural elements. The procedure is implemented with the exception of the differing orientation of the structural elements, substantially as described hereinbefore.
As for example reinforcing cages comprise a large number of stranded wires and accordingly there is also a large number of twisting regions, very many wires have to be twisted for the production of reinforcing cage. Hitherto that has been effected exclusively as a manual operation. As the wires to be used for the twisting operation must also have a certain stability, that activity is exhausting for the persons performing that activity and is also very time-consuming. Because of the manual character of the twisting operation, this also involves irregularly twisted wires. That is admittedly not a serious consideration from the point of view of quality assurance, because of the large number of twistings performed, but a higher degree of reproduction accuracy when twisting wires over adjacent, preferably mutually crossing structural elements, would be desirable.
One or more embodiments are directed to an apparatus for automatically twisting metal wires, in particular for connecting adjacent, preferably mutually crossing structural elements, comprising a wire feed means for feeding wire, preferably endless wire, into the apparatus, an arcuate wire guide which has a selectively openable and closable opening and which is adapted to guide the fed wire in the closed position along the arcuate wire guide from a first side of the arcuate wire guide to a second side of the arcuate wire guide, that is in opposite relationship with respect to the opening, a pulling slider adapted to engage the fed wire on the first side of the arcuate wire guide and to pull it towards the second side of the arcuate wire guide, and a twisting unit adapted to engage the fed wire on both sides of the arcuate wire guide and to twist it by means of a rotational movement.
Advantageous configurations and preferred embodiments and configurations will be apparent from the appendant claims and the description hereinafter.
One or more embodiments of the invention makes use in particular of the realization that automation of the twisting operation makes a crucial contribution to operating in a less fatiguing fashion as in particular the twisting operation requires a great deal of effort.
One or more embodiments of the invention however also goes still further insofar as it provides an apparatus which also makes it possible for the wire to be passed around the twisting region of two or more adjacent, preferably mutually crossing structural elements, in an automated procedure, thereby significantly speeding up the entire working procedure. The interaction of automatedly passing the wire around the twisting region and the automated twisting operation is based on the following central notions: the wire is moved along an arcuate wire guide to ensure a high level of reproduction accuracy in terms of forming the loop by the wire. To be able to arrange the arcuate wire guide which is provided on the apparatus in such a way as to surround the twisting region, there is an opening in the arcuate wire guide. Even in the case of twisting regions which involve difficulties of access, as are to be found for example in relation to reinforcing cages for prestressed concrete components, that makes it possible to easily move the apparatus to the twisting region, engage around the twisting region with an opened arcuate wire guide, and to enclose the twisting region by closing the opening. The mode of operation is for example similar to a tongs arrangement. In addition one or more embodiments of the invention is distinguished in that the wire is pulled along the arcuate wire guide by the pulling slider. The configuration according to one embodiment of the invention of pulling guidance for the wire along the arcuate wire guide can be used for soft wires which permit better twisting than wires of hard material. The apparatus according to one embodiment of the invention, by opening and closing of the arcuate wire guide, makes it possible to place the arcuate wire guide around the twisting region of two structural elements, and the moveable pulling slider then makes it possible to pass the wire which has been fed on one side of the arcuate wire guide, with the arcuate wire guide closed, around the twisting region, along the arcuate wire guide. Finally the twisting unit can then engage the wire which has been passed around the twisting region by the pulling slider on both sides of the twisting region or on both sides of the arcuate wire guide and perform the twisting operation, for example by means of the rotational drive.
Preferably the arcuate wire guide is of a tongs-like configuration and the selectively openable and closable opening is arranged proximally on the apparatus. In this respect—relative to the operational orientation of the apparatus—the term “proximal” is used to mean the end of the apparatus, that is towards the structural elements to be connected.
An advantageous development of one embodiment of the invention provides that the twisting unit has a first wire guide passage hole and a second wire guide passage hole and wherein the wire feed means is adapted to pass the fed wire through the first wire guide passage hole. In that way, it is already possible, when feeding the wire in the direction of the arcuate wire guide, to prepare for later engagement of the wire by the twisting unit. The wire can already be engaged by the twisting unit, by being passed through the wire guide passage hole.
Further preferably the pulling slider is adapted to pass the wire pulled to the second side of the arcuate wire guide through the second wire guide passage hole in such a way that the wire forms a loop from the first to the second wire guide passage hole. What is advantageous with this embodiment is in particular preparation for engagement by the twisting unit on the second side of the arcuate wire guide in one working operation by means of the pulling slider when passing the wire along the arcuate wire guide. As soon as the loop is formed by the wire, it is also immediately passed into the second wire guide passage hole of the twisting unit and passed therethrough.
In a preferred embodiment the apparatus according to one embodiment of the invention has a clamping device which is preferably arranged on the first or the second side of the arcuate wire guide and which is adapted to hold fast the wire passed through the first wire guide passage hole or is adapted to hold fast the wire passed through the second wire guide passage hole. In particular the clamping device is adapted to move the wire after formation of the loop beyond the twisting region of the two structural elements so that twisting by the twisting unit can be further prepared.
Further preferably the apparatus according to one embodiment of the invention has a drive means for wire conveyance, wherein the drive means is adapted to convey the wire passed through the second wire guide passage hole and held fast by the clamping device, to shorten the formed loop to a predetermined size. When the engaged wire is twisted by means of the twisting unit the spacing between the constriction produced by the twisting effect and the structural elements to be twisted becomes less with each revolution. To achieve adequate fixing of the structural elements, a certain minimum number of twists is required. In order on the other hand to use as little wire as possible, the number of twists produced should not exceed a maximum amount. For that reason it is preferable for the spacing between the twisting unit and the structural elements to be limited and defined by reducing the size of the wire loop prior to the twisting operation. It has proven to be particularly preferable to set a loop length which leaves between the twisting unit and the structural elements, an internal spacing which corresponds to the pitch dimension between the first wire guide passage hole and the second wire guide passage hole.
That plane in which lie the points at which the wire is engaged by the twisting unit on the first and second sides of the arcuate wire guide is adopted as the reference point for the twisting unit, when determining the spacing. That plane is preferably perpendicular to the axis of rotation of the twisting unit.
Alternatively it is preferred that the drive means is associated with the wire feed means and is adapted to convey the wire selectively in the feed direction or in opposite relationship to the feed direction. The conveyor direction is primarily made dependent on which of the two sides of the arcuate wire guide the clamping is arranged and holds the wire fast.
In a further preferred configuration the drive means has a drive member which is motor-drivable and is coupled to the pulling slider in such a way that the pulling slider is displaceable selectively from the first side of the arcuate wire guide towards the second side of the arcuate wire guide and from the second side of the arcuate wire guide towards the first side of the arcuate wire guide.
In a further preferred embodiment the twisting unit has two coaxially arranged gears through which the first and second wire guide passage holes respectively completely extend and wherein the two gears are drivable both in opposite directions and also in the same direction. Preferably the two coaxially arranged gears are arranged in directly mutually adjacent relationship. Driving the two gears in opposite directions preferably causes clamping of the wire passed through the first and second wire guide passage holes. That makes it possible for the wire to be engaged by the twisting unit. The drive is preferably implemented by means of a respective servo motor.
As soon as adequate clamping of the wire has been achieved by driving the gears in opposite directions the two gears are preferably drivable in the same direction, more specifically in such a way that the clamping action is maintained while the gears rotate in synchronous relationship to bring about the twisting action by means of rotation of the two wire guide passage holes around a common axis of rotation.
Further preferably the apparatus according to one embodiment of the invention has a cutting body which is arranged to sever the wire within the apparatus and is adapted to sever the wire on the first side of the arcuate wire guide and/or on the second side of the arcuate wire guide. That additionally permits severing of the wire prior to twisting without having to carry separate tools with oneself. The apparatus according to one embodiment of the invention thus permits, in a single continuous working procedure, the feed of wire, passing the wire around an assembly of structural elements that is to be twisted, cutting the wire portion provided for the twisting operation from a wire portion at the feed side, and finally twisting the wire.
The cutting body is preferably in the form of a sharp-edged cutting edge within the apparatus, which is arranged adjacent to the wire passed through the apparatus. Preferably one or both of the gears of the twisting unit have the cutting edge or edges which is or are formed on the gear or gears in such a way that severing is effected when the twisting movement is initiated.
One or more embodiments of the invention further concerns a method of automatically twisting a metal wire for connecting two or more adjacent, preferably mutually crossing structural elements. In one embodiment the method includes the steps:
In regard to the underlying realization and advantages according to the invention attention is directed to the foregoing description relating to the apparatus according to the invention.
A preferable development of the method according to some embodiments of the invention provides that the step of engaging the fed wire by means of a twisting unit includes one or both of the steps:
Further preferably the method includes the step:
In a preferred development of the method it further includes the step:
Further preferably in the method according to one embodiment of the invention the step of engaging the fed wire on both sides of the arcuate wire guide by means of the twisting unit includes:
wherein the step of twisting the engaged wire by means of rotational movement of the twisting unit includes:
Further preferably the method according to one embodiment of the invention includes the step:
One or more embodiments of the invention further concerns the use of an apparatus according to one of the above-described preferred embodiments for automatically twisting metal wires, in particular for connecting adjacent, preferably mutually crossing structural elements, for the production of a reinforcing cage for a pylon element of a wind power installation. The apparatus has in particular:
a wire feed means for feeding wire, preferably endless wire, into the apparatus, an arcuate wire guide which has a selectively openable and closable opening and which is adapted to guide the fed wire in the closed position along the arcuate wire guide from a first side of the arcuate wire guide to a second side of the arcuate wire guide, that is in opposite relationship with respect to the opening, a pulling slider adapted to engage the fed wire on the first side of the arcuate wire guide and to pull it towards the second side of the arcuate wire guide, and a twisting unit adapted to engage the fed wire on both sides of the arcuate wire guide and to twist it by means of a rotational movement. In this case the reinforcing cage as first and second structural elements has a plurality of first and second prestressing cables arranged in mutually crossing relationship. The prestressing cables can optionally be braided together, which facilitates positioning of the prestressing cables prior to twisting of the wire and enhances the stability of the cage.
The advantages of the foregoing developments and preferred embodiments of the apparatus according to the invention also apply to the developments and preferred embodiments of the method according to the invention and the development of the use according to the invention.
The invention is described in greater detail hereinafter by means of an embodiment by way of example and with reference to the accompanying Figures in which:
In the illustrated embodiment the first side 9 of the arcuate wire guide is arranged fixedly relative to the main body 3 while the second side 11 of the arcuate wire guide 5 can be deflected by means of a lever mechanism 15 in such a way that the opening 7 is moved from the closed position shown in
The arcuate wire guide 5 is of a substantially tongs-like configuration and in the interior of the two sides 9, 11 of the arcuate wire guide has a region 27 for receiving adjacent, preferably mutually crossing structural elements.
The arcuate wire guide 5 has a slot 13 extending substantially along the entire arc thereof. The slot 13 subdivides the first side 9 of the arcuate wire guide into two arc portions 9a, 9b. Similarly the slot 13 subdivides the second side 11 of the arcuate wire guide 5 into two arc portions 11a, 11b.
The slot 13 is adapted to receive a pulling slider 23 which is movable along the arcuate wire guide and which is guided by a guide groove 29 arranged internally in the arcuate wire guide.
A twisting unit 25 is arranged at an end of the region 27, that is opposite to the arcuate wire guide 5. The twisting unit 25 is adapted to receive and engage the wire guided along the arcuate wire guide 5, and is further adapted to twist it by rotation about an axis of rotation X.
Arranged at a distal end of the main body 3, that is opposite to the arcuate wire guide 5, is a drive chain 19 which extends partially out of the housing or main body 3 of the apparatus 1. The drive chain has a plurality of guide pins 21 adapted to stabilize and guide the drive chain 19 under a thrust loading.
In regard to the further Figures the same references are used for similar or identical elements. Accordingly, in regard to the description of those elements, in relation to each Figure reference is also directed to the other Figures. In the condition shown in
In addition, in the operating condition shown in
The pulling slider 23 is coupled to the drive chain 19. The movement of the drive chain 19 in both drive directions is ensured by means of a drive pinion 33 arranged drivably on the main body 3 of the apparatus. By suitable driving of the drive chain 19, the pulling slider 23 is guided by means of the groove 29 and moved out of the position shown in
The twisting unit 25 (
The clamping device 41 of the pulling slider 23 is preferably of such a configuration that a first slider member 36, for engagement and clamping of the wire by the pulling slider 23, upon deflection out of an open position, deflects a second slider member 38 which causes clamping of the wire. Coupling of the first slider member 36 to the second slider member is preferably implemented by means of two mutually adapted inclined planes which make it possible for the slider members 36, 38 to slide against each other and which define the direction of movement of the slider members.
The first slider member 36 is preferably arranged on the pulling slider and oriented in such a way that it is moved towards a step 40 upon movement of the pulling slider 23 from the first side towards the second side. The step 40 and the slider member 36 are firstly brought into contact with each other upon the approach of the pulling slider 23 to its end position on the second side. When the pulling slider 23 further approaches its end position on the second side the step 40 pushes against the slider member and displaces it from its relative position on the pulling slider 23 in the direction of its open position (shown in
Preferably the wire guide passage holes 43, 45 are in the form of slots, the slots extending along curved paths. Preferably the curved paths in the first gear 37 are not in coincident relationship with those in the second gear 47. Particularly preferably the curved paths are in the form of circular arcuate portions wherein the center points of the circles, that are associated with the arcuate portions, are arranged eccentrically in relation to the respective gears. That provides that the clamping is particularly gently built up upon relative movement of the gears with respect to each other as the wire guide passage holes in the form of slots are only gradually moved out of their coincident position with the portion of the wire guide passage hole, that is respectively associated with the other gear.
In a preferred embodiment the gears 37, 47 each have a plurality of sets of the wire guide passage holes. It is to be assumed that, in the course of time, wear occurs at the edges of the holes as a result of being acted upon by the clamping force. Gears with a plurality of sets of holes then have the advantage that there is no need for a complete change, but it is only necessary to “advance” the gears to the next set of holes.
With reference to
To prepare for a loop-forming operation the wire is fed in the direction of the pulling slider 23 either manually or by means of a drive device like for example the drive means 49. The wire is engaged by the pulling slider 23 by means of a clamping device 41 and passed from the first side 9 of the arcuate wire guide 5 in the direction of the second side 11 thereof. Optionally, the pulling slider 23 is already partially displaced along the first side 9 of the arcuate wire guide 5 before the arcuate wire guide 5 has become placed completely around the structural elements and the opening 7 is closed again. With the opening 7 closed, the pulling slider 23 is moved completely on to the second side 11 of the arcuate wire guide, where the wire engaged by the pulling slider 23 is transferred to the second wire guide passage hole 45 of the twisting unit 25. In the operation of feeding the wire, the wire has already also been previously passed through the first wire guide passage hole 43 of the twisting unit 25.
Then the wire which forms a loop is clamped fast by means of a wire clamp 46. The pulling slider 23 is released from the wire and moves partly or completely back into its original position again on the first side of the arcuate wire guide 5 (for example as shown in
Before the twisting unit 25 twists the wire by rotation of the two wire guide passage holes 43, 45 around each other, the length of the wire loop formed is preferably shortened to a predetermined dimension dependent on the spacing of the two wire guide passage holes 43, 45 and the required minimum loop length which in turn depends on the thickness of the structural elements.
Shortening of the loop is preferably effected by means of the drive means 49 or by means of again engaging the wire by the pulling slider 23 when the latter has not yet moved completely back into its position on the first side 9 of the arcuate wire guide 5 (
When the loop has reached its predetermined length the gears 37, 39 are firstly driven in opposite directions by means of the gears 47, 48 and the motors connected thereto until sufficient clamping is achieved within the twisting unit 25. In that clamped condition the gears 37, 39 are then driven in the same direction and the wire is severed within the apparatus 1, preferably by means of a cutting body, for example by means of one or more cutting edges on the gears. The twisting unit 25 performs a twisting movement about the axis X subsequently to the severing operation. After the desired number of revolutions the opening 7 is opened again and the apparatus 1 is removed from the twisting region in order for example to perform a subsequent twisting operation.
As will be apparent from the foregoing description the entire procedure in forming the loop and twisting the structural elements is effected in fully automated fashion, which represents significantly easier work for operators.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2012 216 831 | Sep 2012 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2013/065678 | 7/25/2013 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
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| WO2014/044443 | 3/27/2014 | WO | A |
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