Surgical needle abstract
An improved surgical needle is disclosed. The needle has a butt.
The butt has a proximal and a distal end. A blind hole is in the
butt. The hole originates at the proximal and terminates at the
distal end of the butt. A crimp is adjacent to the butt. The improvement
to the crimp comprises a first and a second side that are essentially
parallel. A third side is essentially perpendicular to the first
and second sides. A fourth side is curvilinear. The curvilinear
fourth side can be a semicircle. A machine and a method of attaching
a surgical suture to the improved needle is also disclosed.
Surgical needle claims
I claim:
1. A surgical needle having a butt, the butt comprising a proximal
and a distal end, and having essentially a circular cross section
adjacent to the distal end;
a blind hole in the butt, the hole originating at the proximal
end and terminating at about the distal end of said butt; and
a crimp adjacent to said butt, the improvement to the crimp comprising
a first and a second side that are essentially parallel, the exterior
distance between the first and second sides being from about 11/2
to 3 percent larger than the exterior diameter of said butt adjacent
to said distal end, a third side that is essentially perpendicular
to the first and second side, and a fourth side that is curvilinear,
wherein the length of the curvilinear fourth side is at least about
1.1 times greater than the length of the third side.
2. The needle of claim 1 wherein the fourth side describes an arc
of a circle.
3. The needle of claim 2 wherein the fourth side describes a semicircle.
4. The needle of claim 1 wherein the fourth side describes an arc
selected from the group consisting of an ellipse, a hyperbola and
a parabolia.
5. The needle of claim 1 or 4 wherein the length of the curvilinear
fourth side is at least about 1.7 times greater than the length
of the third side.
6. A surgical needle-suture combination comprising:
a needle having a butt, the butt comprising a proximal and a distal
end, and having essentially a circular cross section adjacent to
the distal end;
a blind hole in the butt, the hole originating at the proximal
end and terminating at about the distal end of said butt;
a monofilament suture strand having two ends, one end of the strand
inserted into the blind hole; and
a crimp adjacent to said butt, the improvement to the surgical
needle-suture combination comprising the crimp having a first and
a second side that are essentially parallel, a third side that is
essentially perpendicular to the first and second side, and a fourth
side that is curvilinear, the length of the curvilinear fourth side
being at least about 1.1 times greater than the length of the third
side, the exterior distance between the third and fourth sides being,
on the axial centerline from more than about 70 to 80 percent of
the exterior diameter of said butt adjacent to said distal end.
7. The needle-suture combination of claim 6 wherein the fourth
side is convex.
8. The needle-suture combination of claim 7 wherein the fourth
side describes a semicircle.
9. The needle-suture combination of claim 8 wherein the distance
between the proximal end of said butt and the crimp is from about
0.002 to 0.010 inches.
10. The needle-suture combination of anyone of claims 8 to 11 wherein
said need is manufactured from a stainless steel wire.
11. The needle suture combination of claim 10 wherein the exterior
distance between the third and fourth sides is up to about 75 percent
of the exterior diameter of said butt adjacent to said distal end.
12. A method of manufacturing a surgical needle-suture combination
the surgical needle having a butt, the butt comprising a proximal
and a distal end, and having essentially a circular cross section
adjacent to the distal end, and a blind hole in the butt, the hole
originating at the proximal end and terminating at about the distal
end of said butt, and a monofilament suture having at least one
filament, the method comprising:
placing said butt of said needle between a first and second die,
the first die having a first and a second side that are essentially
parallel, the distance between the first and second sides being
from about 11/2 to 3 percent larger than the exterior diameter of
said butt adjacent to said distal end, a third side that is curvilinear,
and an opening, the opening being formed by the edges of the third
side being in contact with the opposite edges of the first and second
side, the distance between the third side and the opening formed
by the first and second sides being, on the axial centerline, from
more than about 20 to 80 percent of the exterior diameter of said
butt adjacent to said distal end, and the second die having a planar
surface, the planar surface being essentially perpendicular to said
first and second side and opposite to the third side of said first
die, and the area of said planar surface being larger than the area
of said opening of said first die;
moving a threading block adjacent to said proximal end of said
butt, the threading block having a slot;
aligning the slot of the threading block with said proximal end
of said butt;
inserting one end of the suture into said threading block, through
said slot and into the blind hole of said needle; and
crimping said butt of said needle onto the at least one end of
said suture by closing said first and second die.
13. The method of claim 12 after the crimping step comprising individually
testing the needle-suture combination to obtain a minimum pull-out
value.
14. The method of claim 12 or 13 wherein said needle is manufactured
from a stainless steel wire.
15. The method of claim 14 wherein the distance between the third
side and the opening is up to about 75 percent of the exterior diameter
of said butt adjacent to said distal end.
16. The method of claim 12 wherein the distance between the proximal
end of said butt and the crimp is from about 0.002 to 0.010 inches.
Surgical needle description
BACKGROUND OF THE INVENTION
The most common type of surgical needle is a single use needle
which is crimped to the end of a suture. The needle is used once
and then discarded. It is preferable that the needle have a diameter
that is only slightly larger than the suture.
The single use needle can be a "drilled end" needle.
In this type of needle a concentric hole is formed, usually by drilling
in the butt of the needle. The suture is placed in the hole. The
needle is then crimped around the suture. The crimp must be strong
enough to enable the suture to remain attached to the needle during
the in-vivo placement of the needle and the passing of the suture
through tissue.
After the suture approximates the tissue, it is frequently convenient
to detach the needle so that the ends of the suture can be tied
together without the needle(s). Cutting of the suture with scissors
or a scapel is a convenient method of disengaging the needle. This
requires an extra instrument and an extra manipulation. Some surgeons
use commercially available pull-off needles. The pull-off values
for these needles are in conformity with U.S. Pharmacopeia (abbreviated
"USP" herein) requirements.
In addition to size of the needle and suture, which can effect
the strength of the needle-suture attachment, other variables can
be the surface smoothness of the suture and needle lubricants. Some
needles are lubricated with a silicone rubber or polytetrafluoroethylene
to reduce tissue drag in use. The needle hole can be filled with
zylene or another volatile solvent during coating to reduce the
penetration of the lubricant into the needle hole.
In many instances each needle-suture combination is nondestructively
tested to a minimum pull-off value in routine production. Only those
that pass a test load are accepted for further processing.
Conventional crimp operations are difficult to control. Usually,
crimping is between dies that close to a fixed gap, and any variation
in the crimp dies, the needle size, the hole size and the suture
size changes the degree of crimp. Quality control is likewise difficult.
Other approaches such as crimping to a controlled pressure, or
using a combined pressure and gap cycle have been considered. The
usual approach is to increase the degree of crimp until the crimping
shears off the suture on a test sample, then back off on the degree
of crimp until the sutures are not sheared off, and pull-off above
USP limits, and after testing a representative group of sutures,
proceeding to production.
The attachment of surgical needles to surgical sutures is an ongoing
mechanical problem which is most challenging. There is a continuous
trend towards eyeless needles in which the end of the suture is
fixed to the needle so that the suture is pulled axially through
the tissue causing a minimum of trauma. The attachment must be one
which (a) is predictably secure, (b) causes a minimum of damage
to tissue, (c) is convenient for the using surgeon, (d) permits
sterilization and (e) entails reasonable costs, so that the suture
needle may be attached economically. The attachment must stand up
under the rigors of manufacture, sterilization, storage, shipment
and use.
In theory, if all process parameters are perfectly controlled,
replicate results are obtained. In practice, so many factors enter
that adequate control in production is easier to describe than accomplish.
To develop the background of this invention, the following references
are disclosed:
U.S. Pat. No. 3125095 issued to D. Kaufman, G. Buccino and A.
Glick on Mar. 17 1964 and is entitled "Flexible Stainless
Steel Sutures". This patent discloses generally the manufacture
of a coated multifilament steel suture, and specifically in FIG.
3 and column 5 lines 19 to 30 the crimping of the same into a drilled
end needle.
U.S. Pat. 4054144 issued to J. Hoffman and P. Marsland on Oct.
18 1977 and is entitled "Short-Crimp Surgical Needle".
Related U.S. Pat. Nos. 4060885 and 4072041 issued on Dec. 6.
1977 and Feb. 7 1978 respectively. These patents respectively
disclose a needle-suture combination, and a process and dies for
manufacturing the same. These patents generally relate to the attaching
of a surgical suture to a drilled end needle. There is also a thorough
discussion with cited references relating to the background and
development of the art.
All of the above cited U.S. patents are incorporated herein by
reference.
SUMMARY AND DETAILED DESCRIPTION OF THE INVENTION
The following embodiments summarize the inventions described in
this application:
1. A surgical needle having a butt, the butt comprising a proximal
and a distal end, and having essentially a circular cross section
adjacent to the distal end;
a blind hole in the butt, the hole originating at the proximal
end and terminating at about the distal end of said butt; and
a crimp adjacent to said butt, the im-provement to the crimp comprising
a first and a second side that are essentially parallel, the exterior
distance between the first and second sides being from about 11/2
to 3 percent larger than the exterior diameter of said butt adjacent
to said distal end, a third side that is essentially perpendicular
to the first and second side, and a fourth side that is curvilinear.
2. The needle of embodiment 1 wherein the fourth side describes
an arc of a circle.
3. The needle of embodiment 2 wherein the fourth side describes
a semicircle.
4. The needle of embodiment 1 wherein the fourth side describes
an arc selected from the group consisting of an ellipse, a hyperbola
and a parabola.
5. The needle of embodiment 1 to 4 wherein the length of the curvilinear
fourth side is at least about 1.1 times greater than the length
of the third side.
6. The needle of embodiment 1 or 4 wherein the length of the curvilinear
fourth side is at least about 1.7 times greater than the length
of the third side.
7. A surgical needle having a butt, the butt comprising a proximal
and a distal end, and having essentially a circular cross section
adjacent to the distal end;
a blind hole in the butt, the hole originating at the proximal
end and terminating at about the distal end of said butt; and
a crimp adjacent to said butt, the improvement to the crimp comprising
a first and a second side that are essentially parallel, the exterior
distance between the first and second sides being from about 11/2
to 3 percent larger than the exterior diameter of said butt adjacent
to said distal end, a third side that is essentially perpendicular
to the first and second side, and a convex fourth side, the exterior
distance between the third and fourth sides being, on the axial
centerline, from about 65 to 85 percent of the exterior diameter
of said butt adjacent to said distal end.
8. The needle of embodiment 7 where the fourth side describes a
semicircle.
9. A surgical needle-suture combination comprising:
a needle having a butt, the butt comprising a proximal and a distal
end, and having essentially a circular cross section adjacent to
the distal end;
a blind hole in the butt, the hole originating at the proximal
end and terminating at about the distal end of said butt;
a suture strand having two ends, at least one end of the strand
inserted into the blind hole; and
a crimp adjacent to said butt, the improvement to the surgical
needle-suture combination comprising the crimp having a first and
a second side that are essentially parallel, a third side that is
essentially perpendicular to the first and second side, and a fourth
side that is curvilinear, the length of the curvilinear fourth side
being at least about 1.1 times greater than the length of the third
side, the exterior distance between the third and fourth sides being,
on the axial centerline, from about 65 to 85 percent of the exterior
diameter of said butt adjacent to said distal end.
10. The needle-suture combination of embodiment 9 wherein the fourth
side is convex.
11. The needle-suture combination of embodiment 10 wherein the
fourth side describes a semicircle.
12. The needle suture combination of embodiment 9 or 10 or 11 wherein
one end of the suture strand is inserted into the blind hole.
13. The needle-suture combination of embodiment 12 wherein said
suture strand is a monofilament.
14. The needle-suture combination of embodiment 13 wherein the
exterior distance between the third and fourth sides is from about
70 to 80 percent of the exterior diameter of said butt adjacent
to said distal end.
15. The needle-suture combination of embodiment 13 wherein the
distance between the proximal end of said butt and the crimp is
from about 0.002 to 0.010 inches.
16. The needle-suture combination of embodiment 12 wherein said
suture strand is a braid.
17. The needle suture combination of embodiment 16 wherein the
exterior distance between the third and fourth sides is from about
65 to 75 percent of the exterior diameter of said butt adjacent
to said distal end.
18. The needle-suture combination of embodiment 9 or 10 or 11 wherein
the two ends of the suture strand are inserted into the blind hole.
19. The needle-suture combination of embodiment 18 wherein said
suture strand is a monofilament.
20. The needle-suture combination of embodiment 19 wherein the
exterior distance between the third and fourth sides is from about
65 to 70 percent of the exterior diameter of said butt adjacent
to said distal end.
21. A method of manufacturing a surgical needle-suture combination,
the surgical needle having a butt, the butt comprising a proximal
and a distal end, and having essentially a circular cross section
adjacent to the distal end, and a blind hole in the butt, the hole
originating at the proximal end and terminating at about the distal
end of said butt, and the suture having at least one filament, the
method comprising:
placing said butt of said needle between a first and second die,
the first die having a first and a second side that are essentially
parallel, the distance between the first and second sides being
from about 11/2 to 3 percent larger than the exterior diameter of
said butt adjacent to said distal end, a third side that is curvilinear,
and an opening, the opening being formed by the edges of the third
side being in contact with the opposite edges of the first and second
side, the distance between the third side and the opening formed
by the first and second sides being, on the axial centerline, from
about 65 to 85 percent of the exterior diameter of said butt adjacent
to said distal end, and the second die having a planar surface,
the planar surface being essentially perpendicular to said first
and second side and opposite to the third side of said first die,
and the area of said planar surface being larger than the area of
said opening of said first die;
moving a threading block adjacent to said proximal end of said
butt, the threading block having a slot;
aligning the slot of the threading block with said proximal end
of said butt;
inserting at least one end of the suture into said threading block,
through said slot and into the blind hole of said needle; and
crimping said butt of said needle onto the at least one end of
said suture by closing said first and second die.
22. The method of embodiment 21 after the crimping step comprising
individually testing the needle-suture combination to obtain a minimum
pull-out value.
23. The method of embodiment 21 or 22 wherein one end of the suture
strand is inserted into the blind hole.
24. The method of embodiment 23 wherein said suture strand is a
monofilament.
25. The method of embodiment 24 wherein the distance between the
third side and the opening is from about 70 to 80 percent of the
exterior diameter of said butt adjacent to said distal end.
26. The method of embodiment 24 wherein the distance between the
proximal end of said butt and the crimp is from about 0.002 to 0.010
inches.
27. The method of embodiment 23 wherein said suture strand is a
braid.
28. The method of embodiment 27 wherein the distance between the
third side and the opening is from about 65 to 75 percent of the
exterior diameter of said butt adjacent to said distal end.
29. The method of embodiment 21 or 22 wherein the two ends of the
suture strand are inserted into the blind hole.
30. The method of embodiment 29 wherein said suture strand is a
monofilament.
31. The method of embodiment 30 wherein the distance between the
third side and the opening is from about 65 to 70 percent of the
exterior diameter of said butt adjacent to said distal end.
32. A machine having a first and a second die for crimping a surgical
suture to a needle, the first die having a first and a second side
that are essentially parallel, a third side that is curvilinear,
and an opening, the opening being formed by the edges of the third
side being in contact with the opposite edges of the first and second
side; and the second die having a planar surface, the planar surface
being essentially perpendicular to said first and second side and
opposite to the third side of said first die, and the area of said
planar surface being larger than the area of said opening of said
first die.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial side view of a needle-suture combination of
this invention;
FIG. 2 is a partial, sectional side view showing a crimped blind
hole in the butt of a needle;
FIG. 3 is a partial perspective view of the needle-suture combination
of FIG. 1 adjacent to the butt of the needle;
FIG. 4 is a front view of FIG. 2 taken along the plane 4--4 of
FIG. 3;
FIGS. 5 and 6 are side and front views, respectively, showing the
relationship of the needle butt to the crimping dies, with FIG.
5 additionally showing the relationship of the blind hole to the
threading block;
FIG. 7 is a partial perspective view of an alternative to the needle-suture
combination of FIGS. 1 and 3;
FIG. 8 is a sectional view of FIG. 7; and
FIG. 9 is a sectional view of a alternative to the needle-suture
combination of FIG. 7.
It has been found that the attachment characteristics of a surgical
suture to a surgical needle can be more precisely controlled by
using this invention.
Besides the shape of the crimp and die more fully described herein,
this invention uses a short crimp. A short crimp is one in which
the crimped portion of the needle is less than the length of the
suture end which is inserted into the needle. This provides an uncrimped
section distally of the crimp. The uncrimped end of the suture must
be pulled through the crimp to effect a pull-off.
By requiring that the uncrimped suture end be pulled through the
crimp, as well as the friction of the suture in the crimp, it is
practical to achieve consistent crimp retention, or a predetermined
pull-out value.
In a manufacturing process, it is not practical to make separate
measurements on each individual suture and needle before they are
assembled, and then modify the degree of crimp for these particular
measurements. Instead, it is necessary to use the same swage die
settings. In practice, it is customary to use the same swaging die
settings on a production run, with adjustments made if required
by quality assurance.
From the production standpoint, it is feasible to test the maximum
pull-out value on only representative samples, because the test
is destructive and the samples are discarded after testing. Consequently,
minimum pull-out values are usually the acceptable standard for
quality assurance.
FIGS. 1 and 3 describe a needle-suture combination of this invention.
FIGS. 7 to 9 describe an alternative needle-suture combination of
this invention wherein both ends of the suture are inserted into
the blind hole 5 of the butt 2 (fully shown in FIG. 6). The needle
1 comprises a butt 2. The butt has a proximal end 3 and a distal
end 4. A blind hole 5 in the butt 2 originates at the proximal end
3. The termination point 5a of the hole 5 is at about the distal
end 4 of the butt 2. A crimp, which is shown by the D dimension
in FIGS. 3 and 7 and is intermediate the proximal end 3 and distal
end 4 of the butt 2 attaches the needle 1 to the suture 20.
Referring to FIGS. 7 and 8 both ends of the suture 20 can be inserted
into the butt 2 of the needle. The termination point 5a of the hole
5 (shown in FIG. 6) is at about the distal end 4 of the butt 2.
The flat crimped portion 18 of the butt 2 is essentially synonymous
with the D dimension, which for a looped monofilament suture is
described in Table 3. For aesthetic and possibly other reasons,
it is preferred to have an uncrimped portion 12 adjacent to the
proximal end of the butt 2.
The conventional method for inserting both ends of the suture 20
into the blind hole 5 includes a plug 21. The plug 21 aids in maintaining
both ends of the suture 20 in the blind hole 5 after crimping.
FIG. 9 is an alternative to the use of the plug 21 shown in FIGS.
7 and 8. Because of the geometrical design and dimensions of the
crimp (shown, e.g., in FIGS. 5 and 6), and by controlling the diameter
of the distal end 4 of the butt 2 it may be possible to eliminate
the plug 21 while maintaining the integrity of both ends of the
suture 20a in the blind hole 5.
Referring to FIGS. 2 and 4 the crimp comprises a first side 6
and a second side 7. The first side 6 and second side 7 are essentially
parallel. A third side 8 is essentially perpendicular to the first
and second sides. A fourth side 9 is curvilinear. In one embodiment,
the fourth side 9 is convex to the remaining first, second and third
sides. In a specific embodiment, the convex fourth side 9 is a semicircle.
Referring to FIGS. 5 and 6 a machine for crimping the butt 2 of
the needle shown in FIGS. 1 and 7 to 9 to the suture 20 is described.
The machine comprises a first die 40 and a second die 41. The first
die has a first side 46 and a second side 47. The first and second
sides are essentially parallel. A third side 49 is curvilinear.
In one embodiment, the curvilinear third side 49 is convex. In a
specific embodiment, the convex third side is semicircular.
Referring again to FIGS. 5 and 6 an opening 45 is formed by the
edges of the third side 49 being in contact with the opposite edges
of the first 46 and second side 47. The second die 41 has a planar
surface 48. The planar surface 48 is essentially perpendicular to
the first side 46 and second side 47 and opposite to the third
side 49 of the first die 40. The area of the planar surface 48 is
larger than the area of the opening 45 of the first die 40.
The A, B+r, and C to E dimensions shown in FIGS. 5 and 6 (the D
dimension is also shown in FIGS. 3 and 7) are more fully described
in Tables 1 to 3. The r (radius) dimension shown in FIG. 6 and described
in the tables is essentially identical to the outside radius of
the butt 2.
TABLE 1.sup.1 ______________________________________ Single End
Monofilament Suture Uncrimped Lower Both Upper Needle Die Dies Die
Dia. (d).sup.2 A.sup.3 (B + r).sup.4 C D E ______________________________________
.050 0.0510 0.0400 .065 .045 .010 .044 0.0450 0.0350 .065 .045 .010
.039 0.0400 0.0300 .065 .045 .010 .034 0.0350 0.0270 .065 .045 .010
.032 0.0330 0.0260 .065 .030 .010 .028 0.0285 0.0220 .065 .030 .010
.026 0.0270 0.0200 .065 .030 .004 .024 0.0245 0.0170 .045 .020 .004
.022 0.0225 0.0160 .045 .020 .004 .020 0.0205 0.0142 .035 .020 .002
.017 0.0173 0.0121 .035 .015 .002 .015 0.0152 0.0107 .035 .015 .002
.013 0.0132 0.0092 .035 .015 .002 ______________________________________
.sup.1 Tolerances for all die dimensions are +0.0005/-0.0000 except
the dimension which is +0.0010/-0.0000. All needle and die dimensions
are in inches. .sup.2 The needle is manufactured from 420 Series
stainless steel wire. .sup.3 Working and operable dimension = (1.02
.+-. .01)d; the dimensions shown are representative. .sup.4 Working
dimension = (0.75 .+-. 0.05)d; operable dimension = (0.75 - 0.05/+0.10)d;
the dimensions shown are representative.
TABLE 2.sup.1 ______________________________________ Single End
Monofilament Suture Uncrimped Lower Both Upper Needle Die Dies Die
Dia. (d).sup.2 A.sup.3 (B + r).sup.4 C D E ______________________________________
.33 0.0132 0.0092 .035 .015 .002 .38 0.0152 0.0107 .035 .015 .002
.43 0.0182 0.0130 .035 .020 .002 .53 0.0225 0.0160 .045 .030 .002
.58 0.0250 0.0170 .045 .030 .002 ______________________________________
.sup.1 Tolerances for all die dimensions are +0.0005/-0.0000 except
the dimension which is +0.0010/-0.0000. All needle dimensions are
in millimeters. All die dimensions are in inches. .sup.2 The needle
is manufactured from 300 Series stainless steel wire. .sup.3 Working
and operable dimension = (1.02 .+-. .01)d; the dimensions shown
are representative. .sup.4 Working dimension = (0.75 .+-. 0.05)d;
operable dimension = (0.75 0.05/+0.10)d; the dimensions shown are
representative.
TABLE 3.sup.1 ______________________________________ Multiple End
Monofilament Suture Uncrimped Lower Both Upper Needle Die Dies Die
Dia. (d) A.sup.3 (B + r).sup.4 C D E ______________________________________
.050.sup.2a 0.0510 0.0325 .065 .045 .010 .062 0.0630 0.0405 .065
.045 .010 .118.sup.2b 0.0470 0.0300 .065 .045 .010 .126 0.0510 0.0325
.065 .045 .010 .138 0.0550 0.0350 .065 .045 .010 .158 0.0630 0.0405
.065 .045 .010 ______________________________________ .sup.1 Tolerances
for all die dimensions are +0.0005/-0.0000 except the dimension
which is +0.0010/-0.0000. All die dimensions are in inches. .sup.2a
The needle for sizes .050 and .062 is manufactured from 420 Serie
stainless steel wire. The dimensions are in inches. .sup.2b The
needle for sizes .118 to .158 is manufactured from 300 Series stainless
steel wire. The dimensions are in millimeters. .sup.3 Working and
operable dimension = (1.02 .+-. .01)d; the dimensions shown are
representative. .sup.4 Working dimension = (0.65 .+-. 0.05/-0.0)d;
operable dimension = (0.70 - 0.05/+0.10)d; the dimensions shown
are representative.
Tables 1 and 2 describe the dimensions for crimping one end of
a monofilament, surgical suture strand, which has been inserted
into the blind hole 5 of the butt 2 e.g. as shown in FIGS. 1 and
3. The needles described in Tables 1 and 2 were manufactured from
420 and 300 series stainless steel, respectively.
Table 3 describes the dimensions for crimping both ends of a monofilament
surgical suture strand, which has been inserted into the blind hole
5 of the butt 2 e.g. as shown in FIGS. 7 to 9. The needles
described in this table were manufactured from 300 and 420 series
stainless steel.
It is to be understood that the dimensions described in the Tables
1 to 3 can be adapted to other alloys, e.g. 455 series stainless
steel. It is also to be understood that the dimensions shown in
Table 3 are representative of dimensions which can be used for crimping
one end of a braided surgical suture strand which has been inserted
into the blind hole 5 of butt 2.
Referring further to FIGS. 5 and 6 a method of manufacturing a
needle-suture combination has been invented. In the method, a threading
block 60 is used. The threading block has a slot 61. The threading
block 60 is moved adjacent to the proximal end 3 of the butt 2 such
that the slot 61 is aligned with the blind hole 5 of the butt 2.
The .alpha. angle adjacent to the termination point 5a of the butt
2 shown in FIG. 5 may operably be from about 25.degree. to 35.degree.;
for the discussions shown in Tables 1 to 3 the .alpha. angle was
30.degree.. The .alpha. angle adjacent to the E dimension shown
in FIG. 5 is not critical to the practice of the invention. However,
at least for aesthetic and possibly for other reasons, it is preferred
to offset the crimp from the proximal end 3 (shown in FIG. 6) of
the butt 2. This .alpha. angle may operably be from about 25.degree.
to 45.degree. for the dimensions shown in Tables 1 to 3 this .alpha.
angle was 30.degree.. |