Abstract:
A clamp arrangement for securing a needle to a needle support member includes an interface arrangement between a first clamp segment, defining an inner end of a baler needle, and a surface of a needle support member, on which a second clamp segment is located on a side of the support member opposite to that engaged by the first clamp segment. The interface arrangement is such as to permit the needle to be rocked sideways so as to adjust an outer twine delivery end of the needle from side-to-side as necessary to bring the twine delivery end in correct alignment with a knotter mechanism.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to balers for making parallelepiped bales and more particularly relates to needle assemblies for such balers. 
       BACKGROUND OF THE INVENTION 
       [0002]    Balers, both large and small, for forming parallelepiped bales typically use a needle assembly including a plurality of needles, cantilever-mounted to a transverse support member, to deliver twine through the bale chamber between adjacent ends of a just finished bale and starting bale to respective knotter mechanisms of a knotter assembly to complete the tie cycle on the finished bale and to start the next. Each of the needles must be accurately positioned at the top of its cycle in order to correctly place the twine in the associated knotter mechanism located on the opposite side of the bale chamber from the area occupied by the needles when the latter are in their at rest or standby position. The support member for the needles is typically mounted for swinging through an arc to move the needles as a unit. In addition to each of the needles having to be properly positioned for placing the twine into the associated knotter mechanism, needle position is also critical as the needles move through the arc because of the close proximity of baler components through which they must pass, e.g., the bale chamber floor and top, the plunger face, and the knotter assembly. 
         [0003]    On large balers, the cantilever connection of each needle is typically through a clamp arrangement. This can consist of two clamp segments that are clamped around a round tube. The length of the tube is perpendicular to the direction of travel of the needle mechanism during the tie cycle. One clamp segment is welded to the tube while the other defines an inner end of a needle. Each clamp segment has a generally semi-cylindrical surface sized to mate with the tube outer surface. The clamp segments each extend around less than half the circumference of the tube which leaves a space between the clamp segments when they are in position so that the clamp segment defining the inner end of the needle can be rotated relative to the tube. Four bolts, one on each corner of a given clamp arrangement, are used to force the clamp against the tube to provide the desired clamping force. The fore-and-aft position of the needle tip can be adjusted by loosening the two bolts at one end of the clamp arrangement and tightening the opposite pair to rotate the needle clamp segment slightly around the clamp tube. Side-to-side needle tip adjustments however cannot be made in this fashion because the clamp-to-tube contact is solid in this direction. Heretofore, side-to-side needle tip adjustments have been made by physically bending each needle until it is correctly positioned. 
         [0004]    The problem to be solved then is how to construct a needle clamping arrangement so as to permit side-to-side needle adjustments as well as fore-and-aft adjustments. 
       SUMMARY OF THE INVENTION 
       [0005]    According to the present invention there is provided a novel needle clamping arrangement. 
         [0006]    An object of the invention is to provide a needle clamping arrangement permitting both side-to-side needle adjustments, as well as fore-and-aft adjustments, of the needle tip. This object is accomplished by clamping arrangements wherein the interface between clamping surfaces of the clamping arrangement is shaped to permit side-to-side as well as fore-and-aft adjustments to be made to correctly position the needle tip. 
         [0007]    This and other objects will become apparent from a reading of the ensuing description together with the appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a side view of a baler needle assembly constructed in accordance with the present invention. 
           [0009]      FIG. 2  is a right side view of the baler needle assembly shown in  FIG. 1 , but showing only one needle and showing in broken lines positions at opposite sides of a desired position which the needle may assume before being adjusted. 
           [0010]      FIG. 3  is a perspective view showing the mounting clamp assembly securing the needle to the needle support member. 
           [0011]      FIG. 4  is a sectional view taken horizontally through the mounting clamp assembly of  FIG. 3 . 
           [0012]      FIG. 5  is a sectional view like that of  FIG. 4 , but showing an alternate embodiment employing a separate mounting piece having an inner cylindrically shaped surface engaged with the needle carrier tube and having an outer surface which is generated by rotating a cylindrical segment about an axis located in a plane bisecting the clamp segment that is fixed to the needle support member. 
           [0013]      FIG. 6  is a sectional view like that of  FIG. 4 , but showing a further alternate embodiment employing a pair of generally semi-cylindrical, tapered shims having ends at their thicker dimensions abutting each other at a central plane passing through the needle. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]    Referring now to  FIG. 1 , there is shown a typical needle assembly  10  used in a baler for making parallelepiped bales. The needle assembly  10  includes a plurality of needles  11  (only one shown) mounted at spaced locations along a tubular cylindrical needle support member  12 , with the total numbr of needles  11  depending on the cross sectional dimension of a bale to be produced by the baler. As is well known, each needle  11  is responsible for delivering a strand of twine through the baling chamber of the baler and to an associated knotter mechanism so that the strand may be tied about a bale, which has reached a desired length in the baling chamber. 
         [0015]    The needle  11  includes an elongate, curved body  14  which increases in width from an inner end drfined by a first clamp segment  16  and an outer, twine-delivery end which carries a roller  18  that is used to engage and guide twine towards a knotter mechanism located on an opposite side of the baling chamber from a location where the support member  12  is mounted for swinging along an arcuate path between a standby position, wherein the needles  11  are located with their outer twine-delivery ends withdrown from, but adjacent to, the baling chamber, and a twine-delivery position, wherein the needles extend through the baling chamber with their outer ends being adjacent respective associated knotter mechanisms. A clamp segment  20 , here shown as a being identical in shape to the clamp segment  16 , is welded in place on the support member  12 . 
         [0016]    As can best be seen in  FIG. 3 , each of the clamp segments  16  and  20  includes a central portion  22  joined to top and bottom flanges  24  and  26 , respectively and have an inner surface  28  shaped substantially complementary to, and engaged with, a cylindrical exterior of the support member  12 . Each of the flanges  24  and  26  contains two holes  30 , with the four holes of each clamp half being elongated in a direction parallel with a longitudinal axis of the support member  12 , arranged in a rectangular pattern, and respectively aligned with the four holes provided in the other clamp half. A bolt  32  is received in each pair of aligned holes  30 , with a shoulder nut  34  and a jam nut  36  being received on a threaded end of each bolt  32 . Instead of four bolts  32  being used, a clamp arrangement employing to U-bolts would work just as well. 
         [0017]    Referring now to  FIG. 4 , it can be seen that inner surface  28  of the clamp segment  16  is tapered from opposite ends to a crown  38  located in a plane in alignment with a plane passing centrally between opposite surfaces of the needle body  14 . This makes it possible to adjust the outer end of the needle body  14  through a range shown in broken lines in  FIG. 2 , by loosening the bolts located on one side of the crown  38 , while tightening the bolts on the other side of the crown  38 . Instead of, or in addition to, the crown  38 , a mirror image to the surface  28  could be provided on the support member  12 . 
         [0018]      FIG. 5  shows an alternative embodiment wherein the inner end of the needle  11  is defined by a clamp segment  16 ″ including an inner surface  28 ′ including a central surface section  42  shaped cylindrically about an axis extending in a direction perpendicular to a central axis of the support member  12 . Seated against the cylindrically shaped central surface section  42  is a cylindrical outer surface of a crown member  44  having an interior surface shaped complementary to, and seated against, the cylindrical exterior of the tubular support member  12 . The crown member  44  may be fixed to the support member  12 , as by welding, for example, and thus may be considered part of the support member, or it may be provided as a separate piece. When the clamp segment  16 ′ is disposed centrally on the crown member  44 , gaps  46  are defined between opposite ends of the inner surface  28 ′ and the support member  12 . If it is necessary to adjust the side-to-side position of the outer end of the needle  11 , this may be done by loosening the nuts  34  and  36  on the bolts  32 , adjusting the clamp segment  16 ′ about the cylindrical surface of the crown member  44  and re-tightening the nuts  34  and  36 . It will be understood that instead of the surface  42  being formed in the clamp segment  16 ′, it could instead be provided as a cylindrically contoured groove in the exterior of the support member  12 , with the crown member  44  then being replaced by a similar member inverted so as to fit the cylindrical surface of the clamp segment  16 ′ and the cylindrical groove provided in the support member  12 . 
         [0019]      FIG. 6  shows and alternate embodiment wherein the inner end of the needle  11  is defined by a clamp segment  16 ″ having an inner surface  28 ″ formed at a radius somewhat larger than the radius of the outer surface of the support member  12 . Inserted between the clamp segment  16 ″ and the support member  12  are two slightly tapered shims or wedges  50  and  52 , having their thicker dimensioned ends engaged with each other at a central plane passing through the needle clamp segment  16 ″. Thus, outer surfaces  54  and  56 , respectively, of the shims  50  and  52  diverge from the inner surface  28 ″ of the clamp segment  16 ″ in opposite directions from the central plane. In effect, the shims  50  and  52  form a crown on the support member  12 . It will be appreciated that a pair of shims could similarly be used to form a crown on the cylindrical inner surface  28 ″ of the clamp segment  16 ″, in which case the shims would have outer, cylindrically curved surfaces. Alternatively, a slightly tapered shim which extends lengthwise, completely through a gap defined between the clamp segment  16 ″ and the outer surface of the support member  12  could be used, with the direction of insertion into the gap depending on the direction in which the needle  11  needs to be cocked in order to appropriately adjust its outer end. 
         [0020]    Thus, it will be appreciated, that by providing an appropriate profile at a clamping surface arrangement of the clamp segments  16 ,  16 ′ or  16 ″ with the support member  12 , clamping forces can be applied to the clamp segments  16 ,  16 ′ or  16 ″ so as to effect side-to-side adjustment of the outer twine-delivery end of the needle  11 . 
         [0021]    Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.