Abstract:
A strip brush ( 10 ) includes a plurality of elongate bristles ( 12 ) and a spine formation ( 14 ), the bristles having first and second free ends ( 16 ) and being gripped by the spine formation ( 20 ) between said ends. The spine formation includes a length of material having first and second spaced folds and the plurality of bristles are trapped between the folds such that the first and second folds define opposing ends of said spine formation. The spine formation is formed of a single sheet of planar material which is folded and/or otherwise deformed into the required profile.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.K. Application No. GB0722694.7, filed 20 Nov. 2007, by the same inventor, the entire contents of which hereby incorporated by reference. 
       BACKGROUND 
       [0002]    The present invention relates to strip brushes. 
         [0003]    Strip brushes generally comprise an elongate spine member, within which a plurality of bristles are held such that a free end of each bristle depends therefrom. 
         [0004]    Such strip brushes are conventionally manufactured in a continuous production flow in which a length of spine material is deformed so as to trap bristles therein. The resulting lengths of strip brush are then cut to the desired length and crimped at each end to form discrete brushes. The substantially rigid spine allows attachment of the brushes to machinery or manual tools. 
         [0005]    The strip brushes produced by this method of manufacture are used for a broad variety of applications across different industries. Numerous applications provide for the use of this form of brush as a sealing member, for attachment to moving machinery. The plurality of tightly packed bristles form a mechanical barrier which substantially inhibits the flow of particulate and/or fluid materials therethrough, dependent on the bristle arrangement and material. 
         [0006]    In one example, polymer bristles may be provided so as to provide a hygienic seal for use in food handling or processing machinery. In another example, the bristles may be formed of metallic strands. Such an arrangement finds one application in the oil and gas industry for use as a mechanical seal for machinery in pipelines. Regardless of the industry requirements, the strip brushes are manufactured in substantially the same manner, such that lengths of strip brush are cut to the required dimensions for the application at hand. 
         [0007]    During use, the free ends of the bristles are typically maintained in contact with an adjacent surface. This causes a contact force such that the bristles can bend or flex in response thereto to maintain the required seal or brushing effect. However, it has been found that the application of contact forces and/or vibrations to the strip brush during use can result in a number of bristles towards the peripheral edges of the strip brush becoming loose and shedding from the ends of the brush. 
         [0008]    The shedding of bristles in this manner causes a problem since they can enter the flow of material through the machinery or the moving parts of the machinery itself. When one considers the use of the strip brushes on food handling equipment or else within fuel pipelines, it will be appreciated that the entrainment of loose bristles into the material being processed is a significant disadvantage which can lead to processed materials being rejected or machine down time. 
         [0009]    It is an object of the present invention to provide an improved strip brush for which the problem of shedding bristles is alleviated. 
       SUMMARY OF THE INVENTION 
       [0010]    According to a first aspect of the present invention there is provided a strip brush comprising a plurality of elongate bristles and a spine formation, the bristles having first and second free ends and being gripped by the spine formation between said ends, wherein the spine formation comprises a length of material having first and second spaced folds and the plurality of bristles are trapped between said folds such that the first and second folds define opposing ends of said spine formation, and wherein the spine formation of formed of a single sheet of planar material which is folded and/or otherwise deformed into the required profile. 
         [0011]    The present invention allows for continuous folded ends of the strip brush in contrast to the discontinuity formed by cut and crimped brush ends. The folded ends of the strip brush are particularly advantageous since the bristles cannot be worked free of the ends during use. Thus the spine forms a loop about the plurality of bristles, trapping the bristles within the spine during use. 
         [0012]    In one embodiment, the first and second folds are substantially parallel with the bristles. The length of spine material may comprise a spine member which may be elongate in shape. The spine member may have a longitudinal axis and the spine member may be folded about first and second axes or fold lines which are substantially perpendicular to the longitudinal axis so as to form the first and second folds. 
         [0013]    The spine member may have opposing edges which meet or overlap part way along the length of the strip brush once formed. The spine formation may therefore comprise a single discontinuity part-way along the length of the spine member rather than at the ends of the brush once formed. 
         [0014]    The spine member may be shaped to provide a first and second opposing wall portions extending between said folds with the bristles disposed therebetween. 
         [0015]    In one embodiment the spine formation is shaped in the form of a trench or channel within which the bristles are held. The first wall portion of the spine member may comprise an outer wall of the channel and the second wall portion may comprise an inner wall of the channel. The channel typically has a base and opposing side walls which define an elongate slot or opening through which the bristles protrude. The channel may be substantially U-shaped in section. The opening may be of smaller width dimension than the base of the channel. 
         [0016]    The bristles are typically bent or otherwise deformed within the spine. 
         [0017]    The spine member may be formed of a strip of material of substantially uniform width which is folded or otherwise formed into the required shape. Alternatively, the spine member may have a first section which forms the first wall portion which is of greater width than one or more further portions which form the second wall portion. 
         [0018]    In one embodiment, a spine support member is provided. The spine support member may take the form of an outer wall member shaped to surround the spine formation. The spine support member is typically of greater strength and or stiffness than the spine formation material and may be shaped to provide for attachment of the strip brush to machinery for use. 
         [0019]    According to a further embodiment of the present invention there is provided a method of manufacture of a strip brush comprising: arranging a plurality of bristles relative to a spine member, formed of a single sheet of planar material, such that first and second ends of the bristles protrude outwardly from the spine member; and providing first and second spaced folds in the spine member such that the spine member surrounds said bristles at a location between said first and second bristle ends wherein said first and second folds define opposing ends of the spine member. 
         [0020]    The spine member may comprise a length of material having opposing first and second edges, wherein the edges meet or overlap when the first and second folds are provided. 
         [0021]    The first and second folds may be positioned so as to provide a strip brush of predetermined length without the need for cutting the brush to size. 
         [0022]    In one embodiment, the spine member is further folded or deformed in an orientation substantially perpendicular to the first and/or second folds. The third fold or deformation may be substantially along the length of the spine. The spine member may be deformed such that it is substantially channel shaped in section. The cross-sectional shape of the spine once formed may be substantially V-shaped or U-shaped or rounded in the form of a partial ellipse or a horseshoe shape. 
         [0023]    Further preferable features of the present invention are defined within the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    One or more specific embodiments of the present invention are described in further detail below with reference to the accompanying drawings, of which: 
           [0025]      FIG. 1  shows a cross-sectional view of a strip brush according to the present invention; 
           [0026]      FIG. 2  shows a plan view of a spine member for use in the manufacture of a strip brush according to the present invention; 
           [0027]      FIG. 3  shows a sectional view through the spine member of  FIG. 2  during manufacture of a strip brush according to the present invention; 
           [0028]      FIG. 4  shows a plan view of the spine and bristles when arranged for manufacture of a strip brush according to the present invention; 
           [0029]      FIG. 5  shows an above view of the spine after formation of the strip brush; 
           [0030]      FIG. 6  shows a cross-sectional view of a strip brush according to a further embodiment of the present invention; 
           [0031]      FIG. 7  shows a plan view of a spine member for use in the manufacture of a strip brush according to a further embodiment of the present invention; and, 
           [0032]      FIG. 8  shows a cross-sectional view of a strip brush according to the present invention having the spine member of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0033]    Turning firstly to  FIG. 1 , there is shown a strip brush  10  according to the present invention in section. The brush  10  generally comprises a plurality of bristles  12  protruding from a spine formation  14 . 
         [0034]    The bristles  12  are elongate in shape and have free ends  16  spaced from the spine formation  14 . The spine formation comprises an inner  18  and outer  20  wall formed of a single piece of resilient material as will be described below. The outer wall  20  is substantially U-shaped or horseshoe shaped in section so as to form a channel or gulley within which the bristles  12  are located. 
         [0035]    The inner wall  18  is positioned within the outer wall  20  and is correspondingly shaped. The inner wall  18  is substantially concentric within the outer wall  20  with the bristles trapped therebetween. It will be appreciated that the channel formed by the outer wall  20  is of slightly greater width than the inner wall such that it can accommodate the inner wall and the bristles therein. The channel of the outer wall  20  has an opening  22  which is elongate in form when viewed from above and through which the bristles extend. 
         [0036]    A mid portion  17  of the bristles  12  is held tightly in the spine formation  14  between the inner  18  and outer  20  walls. In this embodiment the mid portion  17  is substantially equidistant from each end  16  of the bristles  12  such that each free end  16  of the bristles extends to substantially the same distance form the spine formation  20 . The embodiment of  FIG. 1  is thus substantially symmetrical about centerline or axis  26 . 
         [0037]    However, it will be appreciated that the bristles may be held within the spine formation  14  at any point between the opposing ends of the bristle and need not be held about their mid point  28 . The plurality of bristles  12  may be considered to be a collection or else a semi-ordered array in which the orientation of each bristle is substantially fixed, although the exact position of each bristle is subject to change dependent on the interaction between bristles during manufacture. The collection of bristles typically has a width dimension which is greater than its depth and, more typically, the collection has a width dimension (which corresponds to the length of the strip brush) which is an order of magnitude or more greater than the depth. 
         [0038]    It will also be appreciated that, whilst the channel shape of the spine formation is formed by bending of the inner and outer walls at a pair of locations equidistant from the axis  26 , a single bend could be provided or else two or more bends or folds which are not symmetrical about the axis  26 . 
         [0039]    The trapped section  17  of the bristles  12  is deformed within the outer wall  20  about the inner wall  18  such that it conforms substantially to the shape of the channel. 
         [0040]    In use the spine formation provides a substantially rigid portion of the brush which can be use to attach the brush  10  to machinery or the like. 
         [0041]    The spine formation  14  is formed of a resiliently deformable material, which is typically a metal such as mild steel. Other materials can be used dependent on the brush specifications. 
         [0042]    Turning now to  FIGS. 2 to 6 , there is shown the strip brush components during various stages of manufacture. In  FIG. 2 , a generally rectangular sheet  30  of metal spine material is provided. For most applications, an elongate form of planar spine material  30  is provided in order to produce an elongate strip brush. However, shorter strip brushes are also possible in which the length of the brush is closer to the width or height dimension. 
         [0043]    A plurality of bristles  12  (see  FIG. 4 ) are laid laterally across the spine material  30  such that the free ends  16 A and  16 B protrude beyond the perimeter of the sheet material  30 . In this embodiment the bristles are arranged such that they are substantially perpendicular to a longitudinal axis  32  of the spine material  30 . The bristles are arranged substantially across a middle portion of the spine material  30  between fold lines  34  and  36  such that the outer sections  38  and  40  of the spine material are exposed. 
         [0044]    The spine material  30  is deformed about spaced fold lines  34  and  36  so as to produce folds  35  and  37 , resulting in the profile shown in  FIG. 3 . It will be appreciated that the bristles  12  will thus be trapped within the interior  42  of the partially formed spine. However, the bristles  12  are omitted from  FIG. 3  for clarity. 
         [0045]    The folds  35  and  37  are spaced by a distance A which defines the length of the spine formation  14 . The outer regions  38  and  40  are folded over in the form of flaps which are folded back upon the central portion substantially about 180°. The length A and the length of the outer regions  38  and  40  are selected such that the formed flaps overlap when folded flat as shown in  FIG. 3  so as to form an complete enclosure around the inner space  42 . The inner space is generally elongate in form although its width may vary dependent on the depth of bristles to be held therein. 
         [0046]      FIG. 4  shows a plan view of the arrangement of  FIG. 3 , complete with bristles  12 . A further pair of fold lines  44  and  46  are shown in  FIG. 4 . These fold lines are generally parallel with the longitudinal axis  32  of the spine material  30 . In order to produce the sectional shape shown in  FIG. 1 , the spine material is folded about fold lines  44  and  46  by 90° or more such that, when viewed from above the spine formation appears as shown in  FIG. 5 . 
         [0047]    In one embodiment the spine material may be folded by approximately 95° or else until the opposing edges of the inner wall  18  touch. In alternative embodiments, the spine material may be longitudinally folded by less than 90° so as to form an open channel or V-shaped section. 
         [0048]    The folding of the spine material in this manner causes the bristles to be bent back upon themselves such that the free ends  16 A and  16 B protrude from the spine formation  14  in substantially the same direction. Whilst two longitudinal folds  44  and  46  are preferably use to achieve this effect, a single longitudinal fold of approximately 180° may also be used. A single or a plurality of folds may also be tailored to deform the spine material about a curved sectional shaped such that it is rounded in section. All such embodiments are intended to fall within the scope intended by the terms “fold,” “folded,” or “folding.” 
         [0049]    It will be appreciated that the inner  18  and outer walls  20  of the spine formation in  FIG. 1  are formed by folding of the planar spine material  30  to the required shape. 
         [0050]    The folds of  FIGS. 2-5  are typically achieved by mechanical pressing machinery as will be understood by a person skilled in the art. However, the machine settings and angular degree of pressing may be calibrated to suit the required strip brush profile. In addition bespoke dies may be provided, against which the spine material can be pressed in order to achieve the required sectional shape. 
         [0051]    The support formation  48  provides additional strength and rigidity to the spine of the brush and may be provided with a particular profile in order to be fixable within a correspondingly shaped slot on a machine. In one embodiment, the shaping of the spine in this manner allows simple fixation of the strip brush to a machine or device for use without the need for additional fixing means. However, it will be appreciated that conventional fixing means may also be provided. 
         [0052]    In  FIG. 6 , the support formation has a neck region  50  of smaller dimensions that the body portion  52  in which the spine formation  14  is enclosed. The dimensions of the neck region  50  may be tailored to grip the spine formation  14  and/or bristles  12 . The dimension of the neck can also be tailored to control the spread of the bristles  12 . In this embodiment, a relatively weak spine formation  14  can be provided simply to hold the bristles within the spine, whilst the structural strength and sectional shape of the spine can be accommodated by the support member  48 . The separation of these design features allows improved tailoring and flexibility of the strip brush design to meet particular bespoke applications. 
         [0053]    The support member  48  may have straight or angled sides or else may be bulbous or rounded in section as shown in  FIG. 6 . 
         [0054]    The spine support  48  may be preformed into an open tubular arrangement as shown in  FIG. 6  and the spine formation  14  may be inserted longitudinally therein. Alternatively, the spine support material may be deformed about the spine formation  14  during manufacture, for example by crimping pressing machinery. Alternatively, the spine support may be deformed in a continuous or flow like manner by deforming elements as a length of support material is fed through machinery by conveying means. Thus, the support formation can be formed and cut in a manner similar to that of conventional strip brushes without the drawback that bristles can be worked free of the brush once formed. 
         [0055]    Turning now to  FIGS. 7 and 8 , an alternative spine formation is shown to that of  FIG. 1 . The embodiment of  FIGS. 7 and 8  may be used either with or without a spine support formation. 
         [0056]      FIG. 7  shows a spine material  54  which folded in a manner similar to spine material  30 . Indeed the end view of the spine material shown in  FIG. 7  would match the profile shown in  FIG. 3 . The difference between the spine material  54  of  FIG. 7  and the spine material  30  of  FIG. 3  is the starting shape of the blank material. 
         [0057]    The spine material  54  has a central region  56  and outer regions  58  and  60  which are folded about folds  62  and  64  to form overlapping flaps. However, the outer regions or flaps  58  and  60  in  FIG. 7  are of reduced width dimension compared to the central region  56 . Thus when the spine material  54  is folded about longitudinal fold lines in a manner similar to that described in relation to  FIGS. 4 and 5 , the sectional profile shown in  FIG. 8  is formed. 
         [0058]    The spine formation  66  of  FIG. 8  thus has an outer wall  68  formed of the central region  56  of spine material  54  which is similar to the outer wall  20  of  FIG. 1 . However, the inner wall  70  in  FIG. 8  is smaller in dimension and comprises a base section only without inner side walls. This embodiment has the benefit over the embodiment of  FIG. 1  that greater internal space is available within the spine for accommodation of the bristles  12 . This can allow an increased number of bristles  12  to be accommodated or else can allow the longitudinal folds to be achieved with less internal resistance. 
         [0059]    Other features of the embodiment of  FIGS. 7 and 8  are equivalent to those described above in relation to  FIGS. 1 to 5  and are interchangeable as far as practicably possible. 
         [0060]    Any or all fold lines described above need not be marked or otherwise indicated on the spine material  30 . Alternatively any or all fold lines may comprise marked lines of predetermined spacing or else may be embodied by physical features on the spine material such as by way of indents, lines of weakness, sections of increased thickness or the like.