Abstract:
A method for filling a receiver with expanded fibers includes the steps of feeding at least one bundle of fibers from at least one roving; introducing the at least one bundle into a portable tool having a manual gripping element, a spray nozzle, an air supply device connected for supplying air to the nozzle, an extraction system configured to hold the at least one bundle and feed the at least one bundle to the nozzle, and an inlet guide positioned to guide the at least one bundle to the extraction system; and using the air supply device to expand the fibers of the at least one bundle in said spray nozzle, and spray the expanded fibers into the receiver.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
         [0001]    The present application is based on French patent application no. 01/02991, filed on Mar. 2, 2001, which is hereby incorporated by reference herein, int its entirety.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The invention relates to a method and device for inserting, into a receiving housing such as a cavity, or for depositing on a surface, continuous fibers, for example glass fibers, in expanded form, with a view to acoustically and/or thermally insulating the deposition housing or environment.  
           [0004]    2. Description of the Background  
           [0005]    It is known from U.S. Pat. No. 4,569,471, for deadening the noise of an acoustic exhaust muffler for an engine, to fill the space surrounding the exhaust gas discharge cylinder with glass fibers, which fibers consist of continuous glass filaments supplied from a yarn roving and are in the form of a bulked product. There, a glass yarn roving is treated by wheels for stretching out/paying out the yarn, and for guiding the yarn, a braking wheel for controlling the tension in the yarn, and a compressed air apparatus for spraying the yarn into the space that is to be filled, the air injected into the apparatus allowing the filaments to be separated, entangled and sprayed.  
           [0006]    However, this device, installed at a factory for the mass-production of exhaust mufflers requires numerous take-up elements for stretching out, guiding and controlling the tension in the yarn as far as the spraying apparatus. Moreover, it is not possible for this device to be used in other applications of filling or depositing, the receiving elements (cavity or surface) of which are too bulky to be filled in factory, or which are fixed.  
         SUMMARY OF THE INVENTION  
         [0007]    It is therefore an object of the invention to provide a device for filling or depositing expanded fibers, which is simpler to use and more compact than known devices, thus making it lighter in weight and portable.  
           [0008]    It is another object of the invention to provide a method and device for filling or depositing expanded fibers, which is easy to handle and to direct, therefore allowing the fibers to be sprayed in any direction.  
           [0009]    According to a feature of the invention, a device comprises a spraying apparatus for charging, in expanded form, fibers from at least one bundle of fibers taken from at least one roving, the apparatus comprising a portable tool having a manual gripping element, the portable tool comprising a nozzle for spraying the fibers of the at least one bundle; an air supply device connected for supplying air to the nozzle so as to expand fibers of a bundle therein; an extraction system configured to hold the at least one bundle and feed the at least one bundle to the nozzle; and an inlet guide positioned to guide the at least one bundle to the extraction system..  
           [0010]    This device is therefore portable, which has the advantage of enabling it to be used on receiving elements which cannot be transported or which are difficult to access.  
           [0011]    The bundle of the roving may be formed of a number of continuous or discontinuous filaments made of glass or thermoplastic. Depending on the application, it may be envisaged that the device will comprise several rovings, the bundles of which are paid out and bulked by the spraying apparatus together and simultaneously.  
           [0012]    In the case of the use of a single roving, the latter may be portable, being placed in a basket.  
           [0013]    According to one feature, the bundle extraction system has two cylindrical rollers rotating in opposite directions and between which the bundle passes, and an outlet guide arranged at the outlet of the rollers and which takes up the bundle. The rotational speed of the rollers gives the bundle its linear speed of travel.  
           [0014]    According to another feature, a device for guiding the bundle towards the inlet of the apparatus is provided an the outside of the body of the apparatus and consists, for example, of an eyelet or a flexible tube. In the case of several bundles, a device for guiding the bundles is provided on the outside of the body of the apparatus and consists of a row of eyelets arranged along an axis parallel to the axes of rotation of the rollers.  
           [0015]    Preferrably, there is provided a debundling system which consists of an associated spreader bar system at the roving outlet or at the inlet to the spraying apparatus.  
           [0016]    The extraction system advantageously operates using a pneumatic motor.  
           [0017]    According to another feature, the spraying apparatus has the form of a gun, the handle of which constitutes the holding element and houses the pneumatic motor.  
           [0018]    Preferably the air supply to the nozzle and the air supply to the motor came from the same source, such as a pneumatic compressor, so as to simplify the device as far as possible.  
           [0019]    Advantageously, means of recovering air which has been exhausted from the pneumatic motor, consist of a pipe which is connected to the exhaust region of the pneumatic motor and is arranged to open, laterally to the outlet guide. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    Other advantages and features will become apparent in the description which follows with reference to the appended drawings, in which:  
         [0021]    [0021]FIG. 1 is a schematic view of the device of the invention handled by an operator;  
         [0022]    [0022]FIG. 2 is a perspective and internal view of the spraying apparatus according to the invention; and  
         [0023]    [0023]FIG. 3 is a part view of FIG. 2 with several bundles introduced into the apparatus. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0024]    [0024]FIG. 1 shows the portable device of the invention which allows an operator  10  to insert continuous or discontinuous fibers, for example glass fibers, into or onto a receiving element  11  so that the fibers can expand to form a bulked product, regardless of its location and/or ease of access, such as the roof space of a house. The receiving element is defined as any volumetric accommodating housing such as a cavity, a gap, or alternatively any surface onto which the fibers can come to rest.  
         [0025]    According to the invention, at least one roving  20  formed of at least one continuous bundle  21  of fibers, is fed to a bundle spraying apparatus  30  such as the spray gun supplied with compressed air from a compressed gas source  40  such as a compressor or compressed gas reservoir, and sprayed by the spraying apparatus in an expanded form into a receiving element.  
         [0026]    To increase the fiber spray rate, provision may be made for the spraying apparatus to be fed with several roving bundles  21 . Thus, several rovings for example are paid out simultaneously, the rovings being placed on their delivery palette at a distance from the point of spraying. Furthermore, depending on the end-use of the bulked product, each roving may be made of a different material, for example glass or thermoplastic.  
         [0027]    For convenience and depending on the accessibility of the receiving element, when just one feed roving  20  is enough, this roving is then designed to be readily portable. The roving is housed, for example, in a basket with a handle to make it easier to transport and to handle the roving during the fiber spraying operation. It is also possible to find a roving support which is suitable for carrying on the operator&#39;s back.  
         [0028]    The spraying apparatus  30  is in the form of a portable tool, such as a gun, provided with a handle  31  so that it can be held by the operator. The apparatus is built ergonomically so as to best fulfil its portable function. Thus, the gun may be associated with an extension piece, in the manner of a butt, so that it can be wedged under the operator&#39;s armpit, avoiding the need to carry it at arm&#39;s-length when the bulking operation proves fairly long.  
         [0029]    The internal structure of the spraying apparatus  30 , as illustrated in FIG. 2, consists of a bundle feed inlet  32  for a bundle extraction system  33 , an expansion nozzle  34  and an air inlet  35  for introducing the compressed air for spraying the bundle through the nozzle.  
         [0030]    The bundle feed inlet  32  has a guide device  32   a , such as a flexible guide tube, which has an open inlet end  32   b  and an open outlet end  32   c  opening onto the extraction system  33 . The guide device  32   a  may also be in the form of a simple eyelet holding the bundle together.  
         [0031]    The extraction system  33  which is used for paying out and entraining the bundle is made up of two cylindrical rollers  33   a  and  33   b  rotating in opposite directions, between which the bundle  21  is held and passes at a defined speed. The bundle  21  is therefore paid out from the roving and pulled by means of the two rollers which are driven by a motor  33   c.    
         [0032]    The guide device  32   a  together with the front part of the extraction system  33  are arranged on the outside of the body of the apparatus so as to be directly accessible to make it easier to introduce the bundle between the rollers at the start of paying-out.  
         [0033]    The presence of the guide device  32   a  at the inlet to the gun helps to reduce the cohesion of the fibers of the bundle before it is introduced between the two rotating rollers.  
         [0034]    As an option, a spreader box system  22 , well known in the prior art and consisting of at least three small cylinders arranged in a staggered configuration to allow the bundle to pass straddlewise over them, may be provided. This system encourages debundling. The bundle passes through the spreader bar system after it has been paid out from the roving or as it enters the spraying apparatus.  
         [0035]    The drive motor  33   c  for the two rollers is preferably pneumatic because then just one power source must be used. Furthermore, its small size means that it can advantageously be housed in the body of the handle  31  of the gun. Furthermore, as will be seen below, the air supply to the motor via a pipe  36  is made easier because it can operate using the air also supplied to the nozzle  31  for expanding the fibers.  
         [0036]    The extraction system  33  also comprises an outlet guide  37 , such as a rigid tube, arranged between the rollers  33   a ,  33   b  and the nozzle  34 , and through which the bundle  21  passes. The guide  37  has a lateral duct  38 , such as a flexible pipe, connected to the exhaust side of the motor  33   c  to form air recovery means. The exhaust air is thus channelled into the duct  38  to open into the guide  37  and thus induce the bundle  21  to leave the rollers.  
         [0037]    The expansion nozzle  34  is situated downstream of the outlet guide  37 , in the direction in which the bundle is conveyed through the guide. Compressed air is also injected into the nozzle  34  via the air inlet or pipe  35 , transversely to the direction of arrival of the bundle. Advantageously, the air supply to this pipe  35  is the same one as that  36  to the motor  33   c . This air is supplied by the pneumatic compressor  40  associated with two separate pressure reducers  41 ,  42  for regulating the air pressure in each respective pipe  35  and  36 . In may, of course, also be taken from a main compressed air source available at the work site.  
         [0038]    The speed of the air through the nozzle  34  is higher than the linear speed of the bundle so as to cause the filaments or fibers of which the bundle is made to vibrate and explode, that is to say separate its filaments.  
         [0039]    In the use of the device of the invention, the operator takes the portable equipment to the site where the expanded fibers are to be sprayed. The operator manually pays out a portion of bundle  21 , the end of which he threads into the guide device  32   a , then inserts between the two rotating rollers  33   a ,  33   b . The operator then switches on the pneumatic motor  33   c , which causes the rollers to rotate so as to pay out the roving. The exhaust air is recovered via the duct  38  so as to draw the bundle through the outlet guide  37 .  
         [0040]    In parallel with this, compressed air is injected into the nozzle  34  via the pipe  35  so that it arrives at right angles to the direction of the filaments, so as to destroy their initial cohesion and entangle them. The compressed air injected into the nozzle also plays a part in spraying the bundle out of the nozzle in bulked form.  
         [0041]    Having sprayed the desired amount of fiber, the operator stops the spraying apparatus and, for example using scissors, cuts through the bundle leaving the nozzle in expanded form, which means that it is not necessary to rethread the device by once again bringing the bundle between the rollers and trapping it there if the apparatus is to be used again immediately. As an alternative, it is possible to envisage a cutter which, triggered manually, cuts through the bundle leaving the extraction system and/or downstream of the nozzle.  
         [0042]    Of course, several rovings may be paid out simultaneously. The various roving bundles are then introduced into the guide device  32   a  and pinched together in the extraction system  33 .  
         [0043]    If a great many rovings, for example more than four rovings, are paid out simultaneously, the guide device  32   a  may consist of a vertical row of eyelets which are fixed to a common support, the axis of which is parallel to the axes of rotation of the rollers, so as to spread the bundles across the entire width of the rollers (FIG. 3). The bundles are thus pinched between the rollers parallel to one another in a plane parallel to the axes of rotation of the rollers and are paid out at the same speed, without the possibility of there being any slippage of the bundles on each other, which would occur if they were passed through one single guide eyelet.  
         [0044]    Bringing the bundles together at the time of their expansion and spraying ensures better mixing of the bulked product obtained in or on the receiving element  11 . When each roving is made of a different material, the bulking and mixing of the various materials are thus performed simultaneously.