Patent Publication Number: US-2020282480-A1

Title: Cutting device

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/577,229 filed on Nov. 27, 2017, which is a national stage application of International Application No. PCT/GB2016/051513 filed on May 25, 2016, which claims benefit to European Application No. 1508966.7 filed on May 26, 2015. 
    
    
     SUMMARY 
     The present invention relates to a cutting device for use in removing part of a fixing from the body of an aircraft, including the wing of an aircraft and/or the fuselage of an aircraft. In particular, the present invention relates to a hand-held cutting device which, in use, is used to remove a collar mounted on a bolt, the bolt being part of a fixing on the body of an aircraft, including the wing of an aircraft and/or the fuselage of an aircraft. More particularly, the present invention relates to a hydraulically driven cropper for use in removing a collar mounted on or attached to a bolt, the bolt being part of a fixing on the body of an aircraft, including the wing of an aircraft and/or the fuselage of an aircraft. There is also provided the use of the cutting device of the present invention to remove a collar from a bolt fixing located on the body of an aircraft, including the aircraft fuselage and wing assemblies. There is also provided a method of removing a collar mounted on or attached to a bolt, the bolt being part of a fixing on the body of an aircraft, including the wing of an aircraft and/or the fuselage of an aircraft. 
     During the manufacture of aircraft fuselage and wing assemblies thousands of fastenings, comprising a bolt and collar, are used to “bolt together” panels of aluminum alloy and/or carbon fiber sections and the stringers that strengthen the aircraft structure. 
     The bolt fastenings, in particular, bolts are usually countersunk headed at one end thereby providing a smooth/flush joint on the outer surface of the aircraft body or wing and fitted with a conventional crimped collar on the inside. 
     During the manufacture or maintenance of wing or body panels of an aircraft, it is common and desirable to remove some or all of these fastenings so that they may be replaced. To this end, fasteners that include a collar, crimped or otherwise, mounted thereon or attached thereto need to be removed by cutting the collar so that it may be removed from the bolt. 
     As will be appreciated by those in the field of aircraft manufacture and maintenance, the act of removing and replacing collar including fixings on a surface of an aircraft is not only time consuming, but can result in damage to the aircraft, if it is not done properly and/or due to shortcomings with the cutting apparatus or tooling currently utilized to remove the collars. 
     To remove the collar, it is preferable to cut the collar in half, otherwise a “C” shaped portion of the collar will be left behind firmly gripping its associated bolt. It will be appreciated that the subsequent removal of the firmly gripping “C” shaped portion of the collar can be difficult, will be time consuming and can result in damage to the surface of the aircraft adjacent to the collar being removed. 
     The current tooling or tools or cutting apparatus used to remove collars from these bolted fixings are extremely bulky. In some embodiments, the tooling has a remote power supply and comprises trailing compressed air hoses and unwieldy hydraulic hoses connected to the portion of the tool which carries out the actual act of cutting the collar. Due to the shear bulk of these hoses, the tooling is difficult to maneuver into position to carry out the act of cutting the collar. To this end, the remote power supply and the associated hydraulic hoses may need to be repositioned as the operator moves along the portion of the body of the aircraft where the collars are being replaced. Additionally, users have been known to get caught up in the unwieldy hoses resulting in personal injury. 
     Also, the current tooling is very complicated in structure and if a part becomes damaged, the tooling can be out of service for long periods of time due to the long lead time required to get replacement parts from a supplier. In some instances, it can take up to 26 weeks to receive a spare part. 
     It is also known to use hand-held manual collar croppers to cut these collars. Although these hand-held manual collar croppers are less bulky because they do not include the unwieldy hydraulic hoses etc. and hence, easier to maneuver to carry out the cutting process, they do require a substantial amount of manual force to be exerted by the user to actually successfully cut the collar in half. The use of hand held manual collar croppers has resulted in hand injuries and muscle strains. Also, the efficiency of a hand held manual collar cropper is dependent on the fitness and strength of the person using it. As will be appreciated, this can vary substantially from user to user. Additionally, it is difficult to ensure that the cutting force exerted by a hand held collar cropper is uniform. This can result in damage to the bolt from which the collar is being removed. To this end, in some instances, it is preferable that the bolt is reused i.e. it is only the collar of the “bolted fixing” which is being replaced. 
     With a view to at least addressing some of the problems identified above, the present invention provides a hand held hydraulically driven cropper for use in removing the collar from a bolted fixing located on the body of an aircraft, including the wing of an aircraft or the fuselage of an aircraft. 
     In a first aspect of the present invention there is provided a cutting device or cropper for use in cutting a collar which is mounted on a bolt in half, the cutting device comprising: 
     a mouth for receiving the portion of the collar to be cut; 
     a pair of jaws diametrically opposite one another and located within the mouth, 
     each jaw being provided with a cutting blade, 
     a driver for moving at least one jaw relative to the other such that the collar can be cut in half by the action of the jaws moving towards one another. 
     Advantageously, the cutting device includes a guard which, in use, prevents the cutting blade from protruding beyond the mouth and damaging a surface adjacent to the collar to be cut in half. Advantageously, the guard is removeably attachable to the cutting device. Preferably, at least the outer surface of the guard is polished. Further preferably, the guard is provided by two L-shaped or substantially L-shaped members, each located at either side of the entrance to the mouth. 
     Optionally, the cutting device includes a handle and can be hand-held in use. 
     Further preferably, the device is battery powered. Further preferably, the device includes a battery pack, which is preferably removeable. 
     Advantageously, the device comprises a rechargeable battery pack. Further preferably, the rechargeable battery pack is removeable. 
     Preferably, the battery is a lithium-ion battery or a graphene battery. 
     Further preferably, the driver is driven by an integral hydraulic driver system. 
     Advantageously, the jaws are pivotably mounted within the cutting device and the driver causes them to pivot towards one another to cut the collar. 
     Further preferably, the driver is wedge shaped. 
     Advantageously, the cutting device includes a resilient member such that the driver is resiliently biased by the action of the resilient member such that the driver is prevented from causing the jaws to move towards one another prior to the driver being actuated. 
     Further preferably, the device further includes a side guide to center the collar relative to the jaws. Advantageously, the side guide is provided at either side of the mouth. Further preferably, the side guide is provided at one side of the mouth. Further advantageously, the outer surface of a or the side guide is shaped to complement the shape of the outer surface of the collar. Advantageously, the side guide is molded from a plastics material, preferably polyurethane. 
     Further preferably, the cutting blade lies in the same plane as the jaws. 
     Advantageously, the cutting blade lies in a plane which is offset, preferably by 45 degrees, from the plane of the jaws. 
     Preferably, the device further includes a stop member. 
     Advantageously, the cutting device of the present invention including one or more of the features above, is a hydraulic hand-held collar cropper. 
     In another aspect of the present invention there is provided the use of the cutting device of the present invention to remove a collar associated with or attached to a bolt located on the body of an aircraft including the fuselage and wing of an aircraft. 
     In a further aspect of the present invention, there is provided a method for cutting a collar attached to a bolt located on the body of an aircraft, the method involving the use of the cutting device of the present invention. 
     There is also provided a blade or blade member for use with the cutting device of the present invention, wherein the blade is triangular or substantially triangular in cross section. 
     In a further aspect of the present invention, there is provided the use of the blade of the present invention with the cutting device of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting embodiments of the present invention will now be described by way of reference to the accompanying drawings in which: 
         FIG. 1  is a side perspective view of a first cutting device or cropper device of the present invention; 
         FIG. 2  is a cross sectional view of the internal components of the cutting device of  FIG. 1 ; 
         FIGS. 3A-3C  are cross sectional views illustrating the interaction of the internal components during the cutting process; 
         FIGS. 4A-D  are side perspective views of a second embodiment of a cutting device or cropper in accordance with the present invention; 
         FIG. 5  is a cross sectional perspective view of some of the internal components of the cutting device of  FIG. 4 ; 
         FIG. 6  is a front view of a modified third embodiment of a cutting device of the present invention; and 
         FIG. 7  is a view of a blade for use with the cutting device or cropper of the present invention. 
     
    
    
     Before describing the various non-limiting embodiments of the present invention, we would point out that for the sake of consistency we will use the same reference numerals to identify the corresponding parts in the different embodiments of the cutting device of the present invention. 
     DETAILED DESCRIPTION 
     As illustrated in  FIG. 1 , a first hand held cutting device or cropper  10  in accordance with the present invention comprises a handle  12 , which includes a trigger or push button  14 , which when pulled or depressed actuates the cutting device  10 . 
     Attached to one end of the handle  12  is a power source  13 , preferably in the form of a removable, rechargeable battery pack. Preferably, the battery is a lithium-ion battery or a graphene battery. As will be appreciated, it is preferable that the battery pack is readily removable and replaceable such that if the battery is fully discharged, it can be readily replaced thereby reducing the amount of down time in the event that the battery is fully discharged during use. 
     Although not illustrated, the handle  12  houses the hydraulic drive system used to drive the cutting components of the cutter  10 . 
     Attached to the other end of the handle  12  is the housing  11 , which houses the hydraulic drive system and the cutting components. Preferably, the housing includes at least one removable panel to allow easy access to the working components of the cutting device of the present invention. With further reference to  FIG. 1 , the cutting device  10  includes a mouth  16  which is sized to receive a collar  28 , which is to be cut. 
     Staying with  FIG. 1 , the opening of the mouth  16  is flanked at either side by two guards  15 . Preferably, the guards  15  are replaceable. Further preferably, the outer surfaces of the guard are polished thereby providing a smooth outer surface. As will be appreciated, the guard  15  serves two purposes. The first is to prevent the internal components of the cutting device, in particular the cutting blades  18 , coming into contact with the surface of the aircraft adjacent to the base of the collar  28  during the cutting process. The second is that because of the guard  15 , the cutting device  10  will not damage the surface of the aircraft (not illustrated) adjacent the base of the collar  28 , that is, on being placed over the collar  28  to be cut. 
     With particular reference to  FIG. 2 , which illustrates the components of the cutting device  10  housed within the housing  11 , the cutting device  10  includes two opposing jaws  17   a  and  17   b . As illustrated, the jaws  17   a  and  17   b  are pivotally mounted within the mouth  16  of the cutting device  10  by way of fixed spindles  19 . The respective jaws  17   a  and  17   b  pivot about the axis of the spindles  19 . Although bath jaws  17   a  and  17   b  are moveable, it is to be appreciated that the cutting device of the invention could be configured such that one jaw is moveable and the other jaw is stationary. 
     As illustrated, a blade  18  is attached, preferably removeably attached, to each jaw  17   a ,  17   b . Each blade  18  includes a cutting surface or edge  18   a . As it is preferable to cut the collar  28  into two halves, it is preferable that the cutting edges  18   a  of the blade  18  are held by their respective jaws  17   a / 17   b  so that they are diametrically opposite one another or substantially diametrically opposite one another. 
     With particular reference to  FIG. 7 , the blade  18  is preferably triangular in cross section thereby providing at least three cutting edges  18   a ,  18   b  and  18   c . That is, if one cutting edge  18   a  of the blade  18  becomes blunt through use, the blade  18  can simply be rotated through 120 degrees and reattached to its associated jaw  17   a / 17   b  to provide a “new” sharp cutting edge  18   b . Additionally, if the blade  18  is long enough such that when positioned only half or less of the cutting edge  18   a  actually comes into contact with the collar  28  to be cut, once the blade  18  has been rotated three times, it can simply be flipped lengthwise and reattached to its associated jaw  17   a / 17   b . In this situation, the blade  18  provides six cutting edges. 
     Although the blade  18  is described as being preferably triangular in cross section (i.e. tri-blade), it is to be appreciated that any other shape of the blade is envisaged, including a blade which is diamond, trapezoid, rhombus, pentagon, parallelogram or hexagon etc. in cross-section. 
     As will be appreciated, because the blade  18  preferably has more than one cutting surface  18   a / 18   b / 18   c , in the event that a cutting surface  18   a  becomes blunt through use, the act of switching to a non-blunt cutting surface  18   b / 18   c  is relatively easy. This increases the efficiency of the use of the present cutting device  10 , because there is less downtime when replacing a blunt blade. 
     With further reference to  FIG. 2 , the cutting device or collar cropper  10  includes a driving wedge  22 , which is attached or coupled to a driving rod  21 . The driving wedge  22  includes two drive surfaces  24  upon which rollers  29 , mounted on spindles  30 , move. The driving wedge  22  also includes two stop surfaces  23 . 
     The driving wedge  22  and rod  21  are held in its inactive state or rest position by spring member  20 . As illustrated, the spring  20  is helical in construction, although it is to be appreciated that any other suitable form of spring or resilient member may be used to resiliently bias the driving wedge  22  and rod  21  towards the handle  12  i.e. away from the mouth  16  of the cutting device  10 . 
     As illustrated in  FIG. 2 , the guard  15  is preferably L-shaped in configuration and is preferably releasably held between a restrainer black  26  and restraining nut  36 . The benefit of being releasably held is that the act of replacing the guard  15  will be relatively straightforward. Once again, this reduces the amount of downtime in the event that the guard  15  needs to be replaced. 
     In the event that a collar  28  is to be cut, the device  10  is positioned over the collar  28  to be removed such that the collar  28  to be removed is located within the mouth  16  between the jaws  17   a  and  17   b.    
     As shown in  FIG. 2 , a side guide  31  is located on either side of the mouth  16 . The side guides  31  ensure that when the cutting device  10  is located over the collar  28  to be cut, the jaws  17   a / 17   b  are centered so that the collar  28  is cut in half. 
     Once the collar  28  is suitably positioned within the mouth  16  via the side guides  31 , the user will depress the trigger  14  thereby actuating the hydraulic system (not illustrated) located within the handle  12  which causes the drive rod  21  to act against the resilient spring member  20  such that the driving wedge  22  is pushed by the drive rad  20  against the bias of the spring member  20 . 
     As illustrated in  FIGS. 3A-C , as the driving wedge  22  is pushed forward, the rollers  29  make their way up the wedge drive surfaces  24  such that by the action of the wedge drive surfaces  24  making contact with the jaws  17   a / 17   b , cause the jaws  17   a / 17   b  to pivot towards one another about the axis provided by their respective spindles  19  such that the respective cutting edges  18   a  of the blades  18  cut into opposite sides of the collar  28  thereby cutting it in half. To this end, the extent of the pivot and hence the cut, is controlled by the length of the wedge drive surfaces  24  in that when the rollers  29  reach their respective stops  23  on either side of the driving wedge  22 , the cut is complete because the driving wedge  22  cannot move any further. At this point, the hydraulic system is deactivated and by way of the resilient spring  20  and the retraction fingers  15 , the driving wedge  22  is returned to its resting or inactive position. At this point, the user can readily remove the cut collar  28  which is held within the mouth  16  of the cutting device  10 . 
     As will be appreciated, in this embodiment, on carrying out the cutting process, the blade  18  engages with the end of the collar  28  distal to the aircraft surface (not illustrated) on which the collar  28  is located thereby effecting a cut from the top to the bottom of the collar  28 . 
     As illustrated in  FIGS. 4 a -4 d    and  5 , an alternative cutting device  100  in accordance with the present invention is provided. 
     By comparison to the cutting device  10  of the preceding figures, the blades  18  do not lie in the same plane as the jaws  17   a / 17   b , rather the blades  18  are offset relative to the plane of the jaws  17   a / 17   b , preferably by 45 degrees. This enables the device  100  not to be held directly above the collar  28  to cut the collar  28 . This allows the device  100  to be used to cut collars  28  in confined spaces. 
     In addition, and with specific reference to  FIG. 5 , the side guide  31  is provided or located at one side of the mouth  16  and is shaped so as to abut against and hence, center the collar  28  relative to the blades  18 . To this end, the surface of the side guide  31  against which the collar  28  abuts complements the shape of the outer surface of the collar  28 . 
     Furthermore, and with addition al reference to  FIG. 5 , the device  100  is provided with additional stops  50  adjacent the side guide  31 . 
     In this embodiment, the cutting device  100  is placed over the collar  28  to be cut such that the collar  28  is located within the mouth  16 . The user then positions the cutting device  100  such that an outer surface of the collar  28  abuts against the side guide  31  and hence, is centered relative to the blades  18 . Once centered, the driving wedge  28  is actuated via the trigger  14 , thereby cutting the collar  28  in half. By the action of the addition al stops  50 , the cut collar  28  is retained within the mouth space  16 . 
     With specific reference to  FIG. 6 , the side guide  31  provided at either side of the mouth  16  is made from a resilient plastics material, such as polyurethane. In use, the side guides  31  center the collar  28  to be cut and also, actually assist in retaining the respective halves of the cut collar  28  due to the natural give of the plastics material from which it is made. 
     It is to be appreciated that the cutting device of the present invention can be provided with differently sized size guides  31  which are readily interchangeable and replaceable depending on the size of the collar to be cut. 
     It is also to be appreciated that the size guides can be made of a resilient material such that one size enables all sizes of collar to be cut. 
     It is also to be appreciated that the cutting device of the present invention can be used to remove a collar from any bolted fixing provided on the surface of an abject where it is desirable not to damage the surface of the abject adjacent to the collar being removed. 
     In the present specification “comprises” means “includes or consists of” and “comprising” means “including or consisting of”. 
     The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof