Patent Publication Number: US-2019177109-A1

Title: A Stabilising Assembly and a Marking Device

Description:
The present invention relates to a stabilising assembly for stabilising elongate members during a marking thereof. The present invention further relates to a marking device for marking elongate members. 
     Wires and cables of the electrical and optical variety typically comprise an insulating sheath or jacket which surrounds an elongate core. In many applications, including the aerospace industry, it is common to group a number of wires or cables (hereafter referred to as wires) together to form a wire harness, which is surrounded by a jacket and then routed along an aircraft for example, to couple various electronic devices. To ensure that the correct wires are connected to the appropriate terminals of the devices it is common practice to mark or otherwise apply identification indicia on the exterior surface of the harness and each wire associated therewith. The indicia may comprise a simple code, such as an alpha numeric code, and this code is typically applied at preset locations along the length of the wire so that each wire within the harness can be suitably identified and distinguished from other wires in the harness at various locations along the length thereof. 
     The marking of the wires may be performed using an ink-jet or laser printer for example, which apply the indicia to the wire as the wire is passed under a print head. In the case of laser marking, the mark may be formed by ablating a portion of the sheath or by creating a permanent discolouration in a portion of the sheath, whereas with ink-jet printing the mark is formed by directing a stream of ink droplets onto the outer surface of the wire. However, in both cases the wire is marked while it is in motion, as it passes under the print head in a technique known as marking “on-the-fly”, and given that the wires are typically only a few millimeters in diameter, then fine positional control of the wire is required to ensure that the marking is performed at the correct position on the outer surface of the wire. This is particularly relevant in situations where the features of the mark are created using an array or matrix of dots, whereby each dot is formed by a laser pulse or ink-droplet, for example. It is found that any vibration or misalignment of the wire as it passes the print head can result in a misalignment of the dots which can lead to a blurring of the indicia or even a complete misprint of the indicia. 
     In an endeavour to minimise the effects of wire movement, wires are typically marked as they are passed in sliding contact over a surface. The contact of the wire with the surface is found to assist in reducing wire movement. However, a problem with this technique is that variations in the cross-sectional shape of the wire along the length thereof manifest as a lateral movement of the wire as it passes over the surface. This is particularly a problem in situations the wire comprises a non-uniform cross-section, such as with twisted multi-conductor cables. 
     We have now devised a stabilising assembly and a marking device for reducing undesirable movement of elongate members during a marking thereof. 
     In accordance with a first aspect of the present invention, there is provided a stabilising assembly for stabilising elongate members during a marking thereof, the assembly comprising a stabiliser comprising a first jaw having at least a first planar portion and a second jaw having at least a second planar portion, the first planar portion being positioned adjacent the second planar portion and arranged in a face-to-face relation therewith, the first and second planar portions being orientated in a substantially parallel orientation to define a linear channel therebetween along which a member is arranged to pass for marking. 
     In an embodiment, at least one of the first or second jaw is moveable relative to the second or first jaw respectively, to vary a separation of the first and second planar portions. 
     The width of the channel is adjustable so that the planar portions can be brought into contact with the member, which may comprise a wire for example, disposed therebetween. The member is marked within the channel as the member passes along the channel and in this respect, the member is not clamped by the jaws, but rather stabilised to minimise undesirable lateral vibrations thereof. The assembly may be used to stabilise twisted multi-conductor wires and as such, the length of the channel is preferably longer than the length of the period of the twist along the wire. 
     In an embodiment, the stabilising assembly further comprises at least one actuator for moving at least one of the first or second jaws for varying a separation of the jaws. The assembly further comprises a guide arrangement for maintaining the relative orientation of the first and second jaw as the separation of the jaws is varied. In an embodiment, the guide arrangement comprises a first and second key which are coupled to a respective jaw. The guide arrangement further comprises a keyway and at least a portion of the first and second keys are arranged to slide within the keyway. The keyway may be common to both the first and second keys or alternatively, the portion of each key may be arranged to slide within a respective keyway. However, in either scenario, the location of the keys within the keyway is arranged to preserve the orientation of the jaws as the separation therebetween is varied. 
     In an embodiment, the first and second keys are coupled to a central portion of the first and second jaw thereof, respectively. The guide arrangement may further comprise stabilising supports for supporting the jaws at each end thereof. 
     In an embodiment, the stabiliser further comprises an entrance disposed at an upstream end of the channel for receiving the elongate member into the channel and an exit disposed at a downstream end of the channel, via which the member exits the channel. The entrance is defined between a proximal end face of each jaw, which separately comprise a curved surface that extends around an axis orientated substantially transverse to an axis along which the member extends in passing along the channel, such that the proximal end face of each jaw extends from an inner side to an outer side of the stabiliser. The proximal end faces of the jaws thus diverge away from the upstream end of the channel to create an entrance which tapers inwardly toward the channel and thus facilitates the passage of the member into the channel. 
     The exit of the channel is defined between a distal end face of each jaw, which separately comprise a curved surface that extends around an axis which is similarly orientated substantially transverse to an axis along which the member extends in passing along the channel, such that the distal end face of each jaw extends from an inner side to an outer side of the stabiliser. The distal end faces of the jaws thus diverge away from the downstream end of the channel to create an exit which minimises any snagging of the member as it exits the channel. 
     In an embodiment, the proximal end face of the first and second jaw separately comprise a radius of curvature which are substantially the same. 
     In an embodiment, the distal end face of the first and second jaw separately comprise a radius of curvature which are substantially the same. 
     In an embodiment, the radius of curvature of the proximal end faces is greater than the radius of curvature of the distal end faces. 
     In an embodiment, the stabiliser comprises a longitudinal opening which extends along the length of the stabiliser, and is defined between cooperating longitudinal side faces of each jaw. The longitudinal side face of each jaw preferably comprises a planar face which extends from an inner side of the stabiliser to an outer side of the stabiliser, along the length of the channel. The longitudinal side face of each jaw preferably diverge with respect to each other, in a direction which is away from the channel. Accordingly, the longitudinal side face of each jaw cooperate to form a tapered opening such that the member can easily locate within the channel via the longitudinal opening, for example. 
     In an embodiment, the stabilising assembly further comprises a translation mount for suitably positioning the channel relative to the member. 
     In accordance with a second aspect of the present invention, there is provided a marking device for marking elongate members comprising guide means, drive means and a stabilising assembly of the first aspect, the guide means being arranged to guide an elongate member through the channel of the stabiliser as the member is driven along the channel by the drive means, the marking device further comprising a printing device for marking the member within the channel as the member passes along the channel. 
     In an embodiment, the printing device comprises a laser printing device. However, in an alternative embodiment the printing device may comprise an ink-jet printing device. 
     The guide means preferably comprises a guide wheel and the drive means may comprise a drive wheel around which the member is arranged to pass. In an alternative embodiment, the drive means may comprise track arrangement comprising a first and second track which are arranged to grip the member and drive the member through the channel. 
     Whilst the invention has been described above, it extends to any inventive combination of features set out above or in the following description. Although illustrative embodiments of the invention are described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments. 
     Furthermore, it is contemplated that a particular feature described either individually or as part of an embodiment can be combined with other individually described features, or parts of other embodiments, even if the other features and embodiments make no mention of the particular feature. Thus, the invention extends to such specific combinations not already described. 
    
    
     
       The invention may be performed in various ways, and by way of example only, embodiments thereof will now be described, reference being made to the accompanying drawings in which: 
         FIG. 1  is a perspective view of a stabilising assembly according to an embodiment of the present invention; 
         FIG. 2 a    is a view of the stabilising assembly illustrated in  FIG. 1 , from the downstream end; 
         FIG. 2 b    is a side view of the stabilising assembly illustrated in  FIG. 1 ; 
         FIG. 3 a    is a perspective view of the first jaw of the stabilising assembly illustrated in  FIG. 1 , from an inner side thereof; 
         FIG. 3 b    is a perspective view of the jaw illustrated in  FIG. 3 a   , from an outer side thereof; 
         FIG. 3 c    is a perspective view of the second jaw of the stabilising assembly illustrated in  FIG. 1 , from an inner side thereof; 
         FIG. 3 d    is a perspective view of the jaw illustrated in  FIG. 3 c   , from an outer side thereof; and, 
         FIG. 4  is a schematic illustration of a marking device according to an embodiment of the present invention. 
     
    
    
     Referring to  FIGS. 1 and 2  of the drawings there is illustrated a stabilising assembly  10  according to an embodiment of the present invention for reducing vibrations and thus stabilising an elongate member (not shown), so that an external surface of the member can be accurately marked or printed with suitable indicia. For the purposes of illustration, the following description is based on the use of the stabilising assembly for stabilising wires, such as electrical wires, during a marking thereof, but it is to be appreciated that the stabilising assembly may also be used to stabilise other elongate members, including the elongate members from the non-exhaustive list comprising electrical cables, tubing, such as heat shrinkable tubing, and optical fibre cables. 
     The assembly  10  comprises a stabiliser  10   a  having first and second jaw  11 ,  12  (as illustrated in  FIG. 3  of the drawings) which cooperate to stabilise lateral movement of a wire as the wire is passed therebetween. The first and second jaw  11 ,  12  may be formed of a metal or rigid plastics material for example, and comprise a first and second planar portion  13 ,  14  respectively, disposed on a first side  11   a ,  12   a  thereof and which are orientated in a face-to-face relation, substantially parallel to each other. The first and second planar portions  13 ,  14  form an inner side of the stabiliser  10   a  and define a linear channel  15  therebetween. The jaws  11 ,  12  are moveable relative to each other such that the width of the channel  15  can be varied to suit the particular wire diameter. In this respect, one jaw may be fixed and the other may be arranged to move relative to the fixed jaw, or both jaws may be moveable relative to each other. 
     In order to maintain the parallel orientation of the planar portions  13 ,  14  as the channel width is varied, the assembly  10  further comprises a guide arrangement  16 . The guide arrangement  16  comprises a first and second bracket or key  17 ,  18  which are secured to a respective jaw  11 ,  12  by passing bolts  19  through apertures  20  formed in each key  17 ,  18  into internally threaded bores  21  disposed at a central region of each jaw  11 ,  12 , at a second side  11   b ,  12   b  thereof (namely an outer side of the stabiliser  10   a ). A portion of each key  17 ,  18  is arranged to extend away (downwardly in use) from the respective jaw  11 ,  12  and comprises a cross-sectional shape which complements a cross-sectional profile of a linear channel or keyway  23  formed within a mounting block  24 . The keys  17 ,  18  are permitted to slide along the keyway  23 , and the complementary shaped key  17 ,  18  and keyway  23  preserve a relative orientation of the jaws  11 ,  12  as a separation of the jaws is varied. The keys  17 ,  18  may be arranged to pass along a common keyway  23 , or in an alternative embodiment which is not illustrated, the keys  17 ,  18  may be arranged to pass in separate, parallel orientated keyways. 
     The positioning of the keys  17 ,  18  within the keyway  23  and thus the separation of the jaws  11 ,  12  is controlled by an actuator  25  which in the illustrated embodiment is located at the underside of the mounting block  24 , upon a frame  26 . The frame comprises two support arms  26   a,    26   b  which extend to the underside of each jaw  11 ,  12  at a proximal and distal region thereof. Each support arm  26  comprises a first and second stabilising support  27 ,  28  which are arranged to support a proximal end and distal end of the first and second jaw  11 ,  12 . The stabilising supports  27 ,  28  comprise an externally threaded portion (not shown) having a roller bearing  29  disposed at one end thereof and the stabilising supports  27 ,  28  are arranged to screw into internally threaded apertures (not shown) formed in each support arm  26   a,    26   b  such that the roller bearing  29  can contact the underside of the jaws  11 ,  12 . In this respect, the first stabilising supports  27  are arranged to support the proximal and distal region of the first jaw  11  as the first jaw  11  is moved relative to the second jaw  12 , and similarly, the second stabilising supports  28  are arranged to support the proximal and distal region of the second jaw  12  as the second jaw  12  is moved relative to the first jaw  11 . In an embodiment which is not illustrated, the roller bearings  29  may be arranged to locate within a transverse track or recess (not shown) formed within the underside of each jaw at the proximal and distal region thereof, such that the roller bearing  29  can move back and forth along the respective track as the channel width is varied. 
     The stabiliser  10   a  further comprises an entrance  30  disposed at an upstream end of the channel  15 , which is defined between cooperating proximal end faces  31 ,  32  of the first and second jaws  11 ,  12 , and an exit  33  disposed at a downstream end of the channel  15 , which is defined between cooperating distal end faces  34 ,  35  of the first and second jaws  11 ,  12 . The proximal end faces  31 ,  32  separately comprise a curved surface that extends around an axis orientated substantially transverse to an axis along which the wire extends in passing along the channel, such that the proximal end face of each jaw  11 ,  12  extends from an inner side to an outer side of the stabiliser  10   a.  The proximal end face  31 ,  32  of each jaw  11 ,  12  forms a continuous surface with the respective planar portion  13 ,  14  and thus presents a smoothly varying surface for facilitating the transition of a wire from the entrance  30  into the channel  15 . The proximal end faces  31 ,  32  of the jaws  11 ,  12  diverge away from the upstream end of the channel  15  to create an entrance  30  which tapers inwardly toward the channel  15  and thus facilitates the passage of the wire (not shown) into the channel  15 . 
     Similarly, the distal end face  34 ,  35  of each jaw  11 ,  12  comprise a curved surface that extends around an axis orientated substantially transverse to an axis along which the wire extends in passing along the channel, such that the distal end faces  34 ,  35  extend from an inner side to an outer side of the stabiliser. The distal end face  34 ,  35  of each jaw  11 ,  12  similarly forms a continuous surface with the respective planar portion  13 ,  14  and thus presents a smoothly varying surface for facilitating the transition of a wire from the channel  15  to the exit  33 . 
     The stabiliser  10   a  further comprises a longitudinally extending opening  36 , which in use typically comprises an upper region of the stabiliser  10   a,  and is formed between a longitudinally extending planar, side face  37 ,  38  of each jaw  11 ,  12 . The planar faces  37 ,  38  separately extend from the inner side to an outer side of the stabiliser  10   a,  along the length of the channel  15 , and diverge away from the channel  15  (which in use is typically in an upward direction), such that the longitudinal opening  36  forms a tapered opening so that the wire can easily locate within the channel  15 . 
     Referring to  FIG. 4  of the drawings, there is provided a schematic illustration of a wire marking device  100  for marking a wire (not shown) with indicia at preset locations along the length of the wire. In the illustrated embodiment, the wire to be marked is passed into the device  100  from an upstream end (namely, the left hand side when viewed in  FIG. 4 ), between an upper and lower support stage  101 ,  102 . 
     The upper stage  101  is used to support a plurality of guide wheels  103 ,  104  (only two of which are illustrated in  FIG. 4 ) for guiding the wire through the device  100 , a printing device  105  which may comprise a laser or ink-jet print head  105   a  for example, for applying the indicia to the wire and drive means  106  disposed at a downstream end of the device  100  for driving (i.e. pulling) the wire through the device  100 . The drive means  106  may comprise a drive wheel (not shown) or, as illustrated in  FIG. 4 , a track arrangement which comprises a pair of tracks  107  which separately extend along a first and second linear arrangement of rollers  108   a,    108   b.  The tracks  107  are disposed one above the other and arranged such that the tracks  107  contact each other along at least a portion of their length to define a pinch region  109  which is used to grip the wire (not shown). The wire is fed between the tracks  107  and thus the pinch region  109  so that the track arrangement  106  can act to pull the wire through the device at a predefined speed, as determined by the speed of tracks. 
     The lower stage  102  is used to support a further guide wheel  110  which is disposed at a lateral position across the device  100  which is vertically below a region between the upper guide wheels  103 ,  104 , and a stabilising assembly  10  as described above, which is disposed vertically below the print head  105   a.    
     In use, the wire is positioned between the upper and lower stages  101 ,  102  and fed through the tracks  107  of the track arrangement  106 , and then the upper and lower stages  101 ,  102  are brought together so that the wire contacts a lower region of the upper guide wheels  103 ,  104  and an upper region of the lower guide wheel  110  and extends into the channel  15  of the stabilising assembly  10  via the longitudinal opening. When the upper and lower stages  101 ,  102  have been brought together the upper and lower guide wheels  103 ,  103 ,  110  act to tension the wire and guide the wire through the channel  115 , so that the wire extends in free space along a substantially linear path, between the first and second jaws  11 ,  12 . If required, the vertical positioning of the jaws  11 ,  12  can be varied through the use of a translation mount  39  to which the frame  26  supporting the stabiliser  10   a  is coupled. 
     The separation of the jaws  11 ,  12  is subsequently reduced using the actuator  25  until the first and second jaw  11 ,  12 , and particularly the first and second planar portions  13 ,  14  contact opposite sides of the wire with approximately 2 bar of pressure. In this respect, the assembly  10  further comprises a sensor (not shown) for sensing the pressure applied between the jaws  11 ,  12  and the sensor (not shown) is arranged to output a signal to a controller (not shown) for controlling the operation of the actuator  25 . The jaws  11 ,  12  act to constrain lateral movement of the wire within the channel  15  as the wire is pulled along the channel  15  by the track arrangement  106 . The reduced lateral movement thus provides for an improved application of indicia on the external surface of the wire via the print head  105   a  compared to situations where the wire is arranged to simply pass in free space, or otherwise over a surface, under a printing device.