Chamfer forming head for paper roll

A chamfer forming head for paper roll comprising an inner threading hole to receive a rotating head thereof is provided. The front portion of said forming head is provided with an annual recessed surface having the same diameter of a paper roll to be machined. The forming head further comprises a plurality of radial holes disposed equiangularly around the peripheral of the forming head. The radial holes are communicated with the annular recessed surface. Each of the radial holes is received and disposed with a pressing tool which comprises an end portion, a cutout, a pressing surface, an aligning cutting slot and a contacting end. The pressing tool can be readily adjusted within the radial hole such that the contacting end of the pressing face can be raised to a level which is higher than the annular recessed surface. A locking element is provided and disposed within said radial hole such that the pressing tool can be locked up when the pressing tool is adjusted. Wherein the edge of the paper roll can be readily machined by the pressing face of the pressing tool such that a chamfer can be readily attained on the paper roll.

FIELD OF THE INVENTION
 The present invention relates to a forming head, more particularly, to a
 chamfer forming head for paper roll used for winding threads thereon. The
 forming head is formed by cutting without scraps or burrs. On the other
 hand, ventilating holes are provided such that the paper roll is prevented
 from burning.
 DESCRIPTION OF PRIOR ART
 To the paper roll used for winding threads thereon, a chamfering process
 will be performed at one end to remove the hooks which may damage the
 threads wound thereon. Normally, a chamfering tool is applied to remove
 the sharp edge with suitable machine, such as a lathe. However, this
 cutting process having scraps is not suitable for paper roll since it has
 a low density. Besides, the paper roll contains many a fibrous material.
 Even the sharp edge at one end is chamfered, burrs and projected fibers
 will still hook the thread and damage the threads.
 U.S. Pat. No. 5,351,587 teaches the use of a pair of teeth 43 to process
 one end of a nipple 30. U.S. Pat. No. 3,999,452 teaches the use of two
 pairs of cutters 31 and 32 to process one end of a tube. U.S. Pat. No.
 2,218,147 teaches the use of cutting tools 8 to process one end of a pipe
 13. Because these teachings achieve chamfering by direct cutting, they are
 not suitable for processing paper roll.
 Another existing working process is exerting pressure onto the area of the
 paper roll such that a chamfer can be attained. However, even this
 performing process can readily forming a chamfer without scraps or burrs,
 another negative effect is attained since the pressure exerted at a
 certain point will generate a deformation on the paper roll. As the
 pressure exerted onto the paper roll increases from a single point to a
 circle, the frictional forces increases accordingly such that the rotation
 of the paper roll will be negatively influenced. In a worse condition, the
 chamfering area will be burned by the heat resulted from frictional force.
 SUMMARY OF THE INVENTION
 It is the objective of this invention to provide a chamfer forming head
 wherein the problems encountered by the existing techniques can be
 ultimately solved.
 It is still the objective of this invention wherein the chamfering process
 is performed without scraps, low frictional force and the pressure exerted
 is uniformly distributed.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
 Referring to FIGS. 1 to 4, the forming head 1 generally comprises an inner
 threaded hole 18 and an annular recessed surface 11 having same dimension
 to the outer diameter of the paper roll 3 disposed at the front portion.
 When the inner threaded hole 18 is engaged with the outer threaded portion
 21 of the rotating head 2, a suitable tool can be inserted into the
 actuating hole 19 to rotate the rotating head 2 such that it can be firmly
 attached to the forming head 1. When the forming head 1 is rotated by the
 rotating head 2, the direction of rotation is same to the direction of
 rotation of the outer threaded portion 21 into the inner threaded hole 18.
 Accordingly, the forming head 1 will not escape therefrom during
 processing.
 When the edge 31 of the paper roll 3 is pressed by the annular recessed
 surface 11 of the forming head 1, a chamfer can be formed at the edge 31
 of the paper roll 3. However, the contacting area is comparatively large
 which in turn increases the frictional force which will damage the paper
 roll 3. In light of this, the annular recessed surface 11 defines the
 working area such that the paper roll 3 can be prevented from damage
 during working process.
 The formation of chamfer on the paper roll 3 is attained by the pressing
 tool 13 in the present invention. As shown in FIGS. 1, 3 and 4, the
 forming head 1 is provided with a plurality of radial holes 12 disposed
 equiangularly pass through the annular recessed surface 11. The forming
 head 1 has a periphery 14 through which radial holes 12 pass. In the
 preferred embodiment shown, eight (8) radial holes 12 are provided. The
 forming head 1 is also provided with a plurality of threaded holes 15
 corresponding to each of the radial holes 12 at its back portion. Each of
 the radial holes 12 is intersecting with the annular recessed surface 11
 and a pressing tool 13 is disposed therein. The threaded hole 15 is
 further provided with a locking element 16 such that the pressing tool 13
 can be locked up or released.
 The pressing tool 13 is provided with an end portion 131, a cutout 132, a
 pressing face 133, on aligning cutting slot 134 and a contacting end 135.
 The pressing tool 13 is made of tungsten carbide for the advantage of high
 durability. The cutout 132 is meshed with the space within the annular
 recessed surface 11 when the pressing tool 13 is disposed within the
 radial hole 12. Accordingly, the pressing face 133 may execute preset
 functions. When the locking element 16 is released, the pressing tool 13
 can be moved forward and into the radial hole 12. In order to avoid a
 scrap-cutting to the paper roll 3 by the pressing face 133, the contacting
 end 135 of the pressing face 133 is slightly lifted and higher than the
 bottom of the recessed surface 11. The contacting end 135 is defined when
 the forming head 1 is rotated, the end of the pressing face 133 which is
 in contact with the edge 31 of the paper roll 3. By this arrangement, when
 the forming head 1 is rotated, the raised rear end of the pressing face
 133 is pressed against the edge 31 of the paper roll 3, as clearly shown
 in FIG. 4. Accordingly, a chamfer is formed thereof as the pressing face
 133 exerts a pressing force to the paper roll 3. Furthermore, in order to
 prevent the scraping resulted by the pressing face 133, the pressing face
 133 has a convex surface and a sharp cutting end.
 By the forgoing description, the annular recessed surface 11 may readily
 form a chamfer on the edge 31 of the paper roll 3 within a defined working
 scope without the defects of deforming and with excellent working quality.
 The equiangularly distributed pressing tools 13 provides an uniform
 pressing force, a lower frictional force and no scraps or burrs after
 working. Accordingly, a round, smooth chamfer can be readily attained by
 the provision of the present invention. Besides, the burned chamfer is no
 longer occurred.
 Referring to FIGS. 2 and 3, in order to attain a better ventilating effect
 for the forming head 1 during the working process, a plurality of
 ventilating holes 17 are provided between the inner threaded hole 18 and
 the annular recessed surface 11.
 Referring to FIGS. 1, 3 and 4, as describe above, the pressing tool 13 can
 be moved forward into the radial hole 12. In order to attain a better
 result, an adjusting reference is provided. In this embodiment, the
 pressing tool 13 is provided with an aligning cutting slot 134 at the
 outer surface of the end portion 131 and the cutting slot 134 is flushed
 to the pressing face 133. In the peripheral of the forming head 1, a
 primary aligning slot 141 is provided in the position of the periphery 14
 and which is also passing through the center of the radial holes 12.
 Accordingly, the angular difference between the aligning cutting slot 134
 and the primary aligning slot 141 can be used as a reference for raising
 the level of the contacting end 135 of the pressing face 133. In light of
 this, an accurate adjustment can be attained. Furthermore, the aligning
 cutting slot 134 can be readily rotated by a screw driver. When the
 pressing tool 13 is adjusted, the locking element 16 can be locked up such
 that the pressing tool 13 is locked up accordingly.