Abstract:
An assembly for removing chips from a cutting tool working area on a workpiece, comprising: a support structure ( 16 ) for supporting a first end of an axially expandable and collapsible tubular member ( 46 ); a cross-piece ( 34 ) for supporting a second end of the tubular member ( 46 ); at least one biasing spring ( 30,32 ) configured and arranged for resiliently biasing the support structure ( 16 ) and the cross-piece ( 34 ) away from one another; a housing ( 36 ) with a chips-receiving chamber ( 38 ) located adjacent one of said ends of the tubular member ( 46 ) for engagement with the working area of the workpiece, an outlet ( 40, 44 ) from the chamber ( 38 ) of the housing being configured to be connected to a vacuum source for removing chips from the chamber; and a hub portion ( 22 ) located at the other of said ends of the tubular member for engagement with a cutting machine.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates to an assembly for removing chips and cuttings from a cutting working area of a cutting tool on a workpiece. The assembly of the present invention is adapted to be attached to either an axially movable, non-rotating component of a drilling/milling machine and be resiliently biased towards a workpiece in which a hole or a recess is to be formed, or to be attached to a separate fixed support or stand located close to the workpiece and be resiliently biased towards the machine. In particular, but not exclusively, the assembly is adapted to be used together with orbital drilling machines.  
       BACKGROUND OF THE INVENTION  
       [0002]     When forming holes or recesses in a workpiece by means of a drilling or milling machine chips and cuttings generated by a cutting tool and remaining in the vicinity of the hole during the forming thereof can adversely effect the surface quality of the hole being formed.  
       SUMMARY OF THE INVENTION  
       [0003]     An object of the present invention is to provide a chips-removing assembly, which can efficiently collect and remove chips from a cutting working area while at the same time obtaining a full protection of the cutting tool in the zone between an advancing nose portion of the machine and the workpiece during a working operation.  
         [0004]     For this purpose the assembly of the present invention comprises, in its simplest form, a support structure for supporting a first end of an axially expandable and collapsible tubular member; a cross-piece for supporting a second end of the tubular member; at least one biasing spring configured and arranged for resiliently biasing the support structure and the cross-piece away from one another, a housing with a chips-receiving chamber located adjacent one of said ends of the tubular member for engagement with the working area of the workpiece, an outlet from the chamber of the housing being configured to be connected to a vacuum source for removing chips from the chamber; and a hub portion located at the other of said ends of the tubular member for engagement with a cutting machine. During the working operating the tubular member surrounds the shaft of the cutting tool and defines a space which is substantially closed against a nose portion (e.g. a rotating spindle) of the working machine and which communicates with the chips-receiving chamber so as to improve the evacuation of chips therein and to create a safe protection for the operator in case of a breakdown of the cutting tool.  
         [0005]     Further features and suitable embodiments of the assembly of the present invention are defined in the claims and will be described more in detail in the following description under reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is a perspective view of a first, simple embodiment of the assembly of the present invention;  
         [0007]      FIG. 2  is perspective view of a second embodiment of the assembly of the invention, as seen from a frontal side;  
         [0008]      FIG. 3  is perspective view of the second embodiment of the assembly of the invention, as seen from a rear side;  
         [0009]      FIG. 4  is an end view of the second embodiment of the assembly;  
         [0010]      FIG. 5  is a cross-sectional view taken along the line A-A in  FIG. 4 ;  
         [0011]      FIG. 6  is a perspective view of an orbital drilling machine to which the assembly of  FIG. 2-5  is attached.  
         [0012]      FIG. 7  is a perspective view similar to  FIG. 6  and illustrates a similar orbital drilling machine coordinated with a third embodiment of a cuttings-removing assembly of the present invention;  
         [0013]      FIGS. 8 and 9  are perspective views of the assembly of  FIG. 7 , seen from the rear side thereof and in an axially collapsed and expanded position, respectively; and  
         [0014]      FIG. 10  is a side view of a front portion of an orbital cutting machine and the third embodiment of the assembly in a retracted, unexpanded position in which a tool exchanging operation may take place. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0015]      FIG. 1  illustrates a first, simple embodiment of the assembly  1  of the present invention, comprising a support structure  2  carried on a stand  3  that can be positioned close to a workpiece (not shown). The support structure  2  holds a housing  4  with a chips-receiving chamber  5  and one end of an axially expandable and collapsible, tubular member  6  consisting of a helically wound strip of steel or similar strong material so as to form a telescopic spring which is resiliently biased towards it expanded condition shown in  FIG. 1 . The other end of the tubular member  6  carries a hub portion  7  with a pressure plate P configured to engage a front portion, e.g. an end surface of a spindle, of a cutting machine (not shown). The hub portion  7  is attached to a cross-piece  8  which connects the hub portion  7  to a linear guide unit  9  at one side of the cutting machine for longitudinal guidance of the expansion and collapsing of the tubular member  6 . A guide block  9   a  of the guide unit  9  is supported on a bracket  10  secured to a stationary machine base B. Guide rods  9   b  attached to the cross-piece  8  are slideable in the guide block  9   a . A handle H is attached to the cross-piece  8  for manually compressing the tubular member  6 . Alternately, this could be achieved by a pneumatic cylinder (not shown) which facilitates an exchange of a cutting tool in the machine. A vacuum conduit C is connected to the chips-receiving chamber  5  for removing chips and cuttings from the working area of the workpiece.  
         [0016]     In use the housing  4  is set into engagement with the surface of the workpiece where a hole or recess is to be formed therein. The telescopic tubular member  6  is allowed to axially expand over the cutting tool and its shaft (not shown) so as to bring the pressure plate P to resiliently engage the advancing spindle of the cutting machine. During the advancement of the cutting tool into the workpiece the tubular member  6  will axially collapse successively against the action of the spring force of the resilient member  6 . The tubular member  6  forms both a confined space communicating with the chips-receiving chamber  5  so as to improve the evacuation of chips therein, and a strong protection of the cutting tool in a zone between an advancing nose portion of the machine and the workpiece during a working operation.  
         [0017]      FIGS. 2 and 3  are perspective views of a second embodiment of the assembly  11  of the invention. The assembly  11  is adapted to be attached to a front portion of an outer housing  12  of an orbital drilling machine  14  ( FIG. 6 ), or any other type of material working machine for drilling or milling holes or recesses in a workpiece, where cuttings and chips are to be removed from the working area.  
         [0018]     The assembly  11  comprises a U-shaped support structure  16  having two opposed side legs  18  with a rear fastening section  20  for fixating the support structure  16  to the axially movable housing  12  of the machine  14 . The legs  18  are interconnected by a central hub portion  22  which has a cylindrical recess  24  for receiving a front end of an orbiting spindle carrying a rotary cutting tool (not shown) with a small axial play between the bottom of the recess and the end of the spindle. To the outer side of each leg  18  is mounted a respective guide block  26  for linear guidance of two guide rods  28 . A cylinder  30  of a pneumatic spring generating a substantially constant spring force is attached to the rear end of each leg  18  and to the guide block  26  and has a piston rod  32  extending through the block  26 . The guide rods  28  and the piston rod  32  are fixated to a respective end of a yoke-shaped pressure foot  34 , which interconnects the two pairs of guide rods  28  and the piston rods  32 . The pressure foot  34  carries a central circular housing  36  defining a chamber  38  for receiving cuttings from the hole or recess being formed in a workpiece against which the pressure foot  34  is biased by the pneumatic springs  30 ,  32 . The chamber  38  communicates with a channel  40 , which extends through a branch  42  of the pressure foot  34  and is connected to a vacuum source (not shown) via a tubular outlet socket  44 . The one end of an axially expandable and collapsible tubular member  46  is attached to the central housing  36 , while the other end is attached to the central hub portion  22  of the support structure  16 . The tubular member  46  is configured to accommodate the cutting tool and to define a substantially closed space around it, which could be reduced in volume when the cutting tool advances into the workpiece. The tubular member  46  preferably consists of a telescopic spring made of a helically wound strip  48  of a spring material, such as spring steel. Such a tubular member  46  may easily be collapsed to an axial dimension substantially equal to the width of the strip  48 . Alternatively, the tubular member  46  may be formed as a resilient bellows. In its most expanded position the axial length of the tubular member  46  is such that the tip of the cutting tool mounted to the orbiting spindle will not protrude from the surface of the central housing  36  which engages the workpiece.  
         [0019]     When starting a hole-forming procedure the pressure foot  34  is held at a maximal extended position relative to the drilling machine by means of the pneumatic springs  30 ,  32 . The housing  12  of the orbital drilling machine  14  is fed axially towards the workpiece by an axial feed motor  50  ( FIG. 6 ) until the pressure foot  34  slightly compresses the tubular member  46  when it contacts the surface of the workpiece. During further axial advancement of the cutting tool into the workpiece, the guide blocks  26  will slide forwardly along the guide rods  28  against the constant spring force of the pneumatic springs  30 ,  32 , while collapsing the tubular member  46  axially. Cuttings and chips generated by the cutting tool will be removed by the vacuum source via the chamber  38 , channel  40  and the outlet socket  44  during the whole cutting operation so that the hole will not be jammed thereby and the environment will be protected from being polluted.  
         [0020]      FIG. 7  is a perspective view similar to  FIG. 6  and illustrates a similar orbital drilling machine  14  coordinated with a third embodiment of a cuttings-removing assembly  52  of the present invention.  FIGS. 8 and 9  are perspective views of this assembly, seen from the rear side thereof and in an axially collapsed and expanded position, respectively.  
         [0021]     In contrast to the second embodiment, the assembly  52  of the third embodiment is configured to be mounted to a support  54 , which is fixed relative to the workpiece  56  during the working of a hole therein. The assembly  52  comprises a central upright member  58  attached to the support  54  via an axially adjustable piston rod  60  ( FIG. 10 ). A cylindrical housing  62  defining a chamber for receiving cuttings from the hole or recess being formed is mounted at the top of the upright  58  facing the workpiece  56 . The housing  62  has an outlet opening  64  which is connected to a vacuum source via a hose (not shown) for removing the cuttings from the working area. An upper and a lower lateral bracket  66  and  68  are attached to the upright  58  for holding a respective upper and lower, fixed end section  70  of a telescopic pneumatic spring unit  72  and  74 . Each spring unit  72 ,  74  further comprises three sections  76 ,  78 ,  80  which are axially extendable by separate pneumatic cylinders. The outermost sections  80  of the spring units are carrying between them a cross-piece  82  having a central ring-shaped pressure plate  84  to be engaged by the outer end surface  86  of the orbiting spindle of the drilling machine. As best seen in  FIGS. 7 and 9 , the telescoping sections  76 ,  78 ,  80  of the spring unit  72  form, in its expanded condition, a stair going downwards, while the corresponding sections of the spring unit  74  form a stair going upwards.  
         [0022]     The cross-piece  82  also holds one end  88  of an axially expandable and collapsible tubular member  90 , the other end  92  of which is attached to the upright  58  concentrically to housing  62 . Like in the first and second embodiments, the tubular member  90  is configured to accommodate the cutting tool and to define a substantially closed space around it, which could be reduced in volume when the cutting tool advances into the workpiece. Thus, the tubular member  90  preferably consists of a telescopic spring made of a helically wound strip  94  of a spring material, such as spring steel. Such a tubular member  90  may easily be collapsed to an axial dimension substantially equal to the width of the strip  94 .  
         [0023]     The pneumatic spring units  72 ,  74  are adapted to generate a substantially constant spring force that bias the tubular member  90  towards the end surface  86  of the tool spindle through the pressure plate  84 . As shown in  FIG. 10 , which is a side elevational view showing the mutual positions of the assembly  52  and the drilling machine  14  during a tool changing phase, the telescopic spring sections  76 ,  78 ,  80  may be retracted by their respective cylinders to provide a free space between the assembly  52  and the drilling machine for enable easy exchange of the cutting tool.  
         [0024]     It should be noted that the pneumatic springs  30  and spring units  72 ,  74  referred to above could alternatively be formed as hydraulic or electric units for controlling the expansion and retraction of the tubular member  46 ,  90 .