U.S. patent application number 11/092958 was filed with the patent office on 2005-08-25 for low mass rotary motor assembly for stent processing.
This patent application is currently assigned to Boston Scientific Scimed, Inc.. Invention is credited to Shedlov, Matthew.
Application Number | 20050184473 11/092958 |
Document ID | / |
Family ID | 31714208 |
Filed Date | 2005-08-25 |
United States Patent
Application |
20050184473 |
Kind Code |
A1 |
Shedlov, Matthew |
August 25, 2005 |
Low mass rotary motor assembly for stent processing
Abstract
A rotary assembly for use in processing a tubular member wherein
the assembly comprises a gripping mechanism, that is moveable from
an open position to a closed position. In the closed position the
gripping mechanism engages at least a portion of the tubular
member. The gripping mechanism is operatively engaged to a piston
that is fluid actuatable from a first position to a second position
by a fluid acting upon the piston, such that when the piston is in
the first position the gripping mechanism is in the closed position
and when the piston is in the second position the gripping
mechanism is in the open position. The assembly defines a circuit
through which the fluid is transmitted to the piston.
Inventors: |
Shedlov, Matthew; (Rockford,
MN) |
Correspondence
Address: |
VIDAS, ARRETT & STEINKRAUS, P.A.
6109 BLUE CIRCLE DRIVE
SUITE 2000
MINNETONKA
MN
55343-9185
US
|
Assignee: |
Boston Scientific Scimed,
Inc.
Maple Grove
MN
|
Family ID: |
31714208 |
Appl. No.: |
11/092958 |
Filed: |
March 29, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11092958 |
Mar 29, 2005 |
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10205878 |
Jul 24, 2002 |
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6874789 |
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Current U.S.
Class: |
279/4.01 |
Current CPC
Class: |
B23K 26/0823 20130101;
Y10T 279/1266 20150115; A61F 2/91 20130101; Y10T 279/12 20150115;
Y10T 279/27 20150115 |
Class at
Publication: |
279/004.01 |
International
Class: |
B23B 031/10 |
Claims
1-10. (canceled)
11. A rotary assembly for use in processing a tubular member, the
assembly comprising: a gripping mechanism; a fluid actuable piston
engaged to the gripping mechanism; a fluid circuit comprising a
first and second fluid transmission lumen each having a first and
second end wherein the second end of the first fluid transmission
lumen and the second end of the second fluid transmission lumen are
in fluid communication with the piston; a fluid input connected to
the first end of the first fluid transmission lumen; a fluid output
connected to the first end of the second fluid transmission lumen;
a motor; a rotary shaft, the rotary shaft being rotatable about a
longitudinal axis, a portion of the rotary shaft being operatively
engaged to the motor and a portion of the shaft capable of
communication with a tubular member to be processed; a third fluid
transmission lumen running along the length of the rotatable shaft
having first and second ends with the second end capable of
communication with a tubular member to be processed; and a third
fluid input connected to first end of the third fluid transmission
lumen.
12. The rotary assembly of claim 1 wherein the first fluid
transmission lumen further comprises a first fluid passageway and
the second fluid transmission lumen further comprises a second
fluid passageway and both the first and second fluid passageways
are connected to the rotary shaft.
13. The rotary assembly of claim 10 wherein the first fluid
transmission lumen further comprises a proximal fluid input
coupling which is connected to the first fluid passageway with a
sealant mechanism.
14. The rotary assembly of claim 10 wherein the second fluid
transmission lumen further comprises a proximal fluid output
coupling which is connected to the second fluid passageway with a
sealant mechanism.
15. The rotary assembly of claim 10 wherein the first fluid
transmission lumen further comprises a distal fluid output coupling
which is connected to the first fluid passageway with a sealant
mechanism.
16. The rotary assembly of claim 10 wherein the second fluid
transmission lumen further comprises a distal fluid output coupling
which is connected to the second fluid passageway with a sealant
mechanism.
17. The rotary assembly of claim 1 wherein the rotary shaft is
connected to a non-rotating mount.
18. The rotary assembly of claim 1 wherein the motor contains a
coolant entry port and the third lumen is connected to the coolant
entry port.
19. The rotary assembly of claim 1 wherein the piston can assume
two positions a first position and a second position, and when the
piston is in the first position the gripping mechanism is closed
and when the piston is in the second position the gripping
mechanism is open.
20. The rotary assembly of claim 1 wherein the rotary shaft further
defines a port capable of fluid communication with a tubular member
to be processed and the rotary shaft wherein the port is
constructed and arranged to regulate the flow of fluid from the
third lumen to the tubular member.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] A stent is a radially expandable endoprosthesis which is
adapted to be implanted in a body lumen. Stents are typically used
in the treatment of atherosclerotic stenosis in blood vessels and
the like to reinforce body vessels and to prevent restenosis
following angioplasty in the vascular system. They have also been
implanted in urinary tracts, bile ducts and other bodily lumen.
They may be self-expanding or expanded by an internal radial force,
such as when mounted on a balloon.
[0004] Delivery and implantation of a stent is accomplished by
disposing the stent about a distal portion of the catheter,
percutaneously inserting the distal portion of the catheter in a
bodily vessel, advancing the catheter in the bodily lumen to a
desired location, expanding the stent and removing the catheter
from the lumen. In the case of a balloon expandable stent, the
stent is mounted about a balloon disposed on the catheter and
expanded by inflating the balloon. The balloon may then be deflated
and the catheter withdrawn. In the case of a self-expanding stent,
the stent may be held in place on the catheter via a retractable
sheath. When the stent is in a desired bodily location, the sheath
may be withdrawn allowing the stent to self-expand.
[0005] In the past, stents have been generally tubular but have
been composed of many configurations and have been made of many
materials, including metals and plastic. Ordinary metals such as
stainless steel have been used as have shape memory metals such as
Nitinol and the like. Stents have also been made of biodegradable
plastic materials. Stents have been formed from wire, tube stock,
etc. Stents have also been made from sheets of material which are
rolled.
[0006] A number of techniques have been suggested for the
fabrication of stents and other tubular members from sheets and
tubes. One such technique involves laser cutting a pattern into a
sheet of material and rolling the sheet into a tube or directly
laser cutting the desired pattern into a tube. Other techniques
involve cutting a desired pattern into a sheet or a tube via
chemical etching or electrical discharge machining.
[0007] Laser cutting of stents has been described in a number of
publications including U.S. Pat. No. 5,780,807 to Saunders, U.S.
Pat. No. 5,922,005 to Richter and U.S. Pat. No. 5,906,759 to
Richter. Other references wherein laser cutting of stents is
described include: U.S. Pat. No. 5,514,154; U.S. Pat. No.
5,759,192; U.S. Pat. No. 6,131,266 and U.S. Pat. No. 6,197,048.
[0008] In some instances, stents are tubular members that have been
provided with a pattern of apertures or holes cut around the
circumference of the tube along most of its length. The resulting
stent is utilized to reinforce the walls of the artery or other
body lumen to reinforce or prevent closing of the artery or lumen,
or to at least prolong the time the artery takes to re-close. The
pattern in a stent is typically cut or etched by a mechanical,
chemical or laser cutting device.
[0009] In manufacturing stents, basic lathe techniques have been
adapted to support the tubing used to form the stent during the
hole cutting process. Some examples of such techniques and
apparatuses used for implementing them are described in U.S. Pat.
No. 5,026,965; U.S. Pat. No. 5,221,824; U.S. Pat. No. 5,744,778 and
U.S. Pat. No. 6,114,653.
[0010] Typically, a piece of tubing is supported between a drive
mechanism and a tail stock support in the manner of a lathe. A
laser cutting tool positioned above the tubing will cut the pattern
by moving relative to the tubing along the length of the finished
stent, the tubing being rotated as necessary to present different
parts of the circumference to the laser cutting tool.
[0011] This manufacturing method has various limitations which
results in a fairly high scrap rate. For example, because the
pattern typically occupies a large percentage of the surface area
of the stent, the stent may sag or bow downwardly during the
cutting process as the pattern is cut and the cut area becomes
larger. This is particularly true for thin walled material of the
type most desirably used to form stents. Accordingly, many stents
are rejected as failing to meet the necessary cut accuracy when
manufactured by the methods used prior to this invention.
[0012] Another limitation that some prior stent manufacturing
processes are affected by is that many of the lathe or other rotary
systems used in machining the stent tube often employ a live
spindle bearing assembly that exits a rotary motor of significant
mass. Such assemblies further include a head stock or collet closer
having draw bar riding inside a set of ball bearings. A collet is
attached to the draw bar and is actuated by a yoke mechanism, which
in turn retracts the draw bar into a tapered sleeve. It is clear
that such high mass assemblies and their associated components are
prone to wear induced complications that may ultimately lead to an
increased chance of partial or even complete system failure. Such
degradation is implicitly related to the high cost of maintaining
such systems.
[0013] All US patents and applications and all other published
documents mentioned anywhere in this application are incorporated
herein by reference in their entirety.
[0014] Without limiting the scope of the invention a brief summary
of some of the claimed embodiments of the invention is set forth
below. Additional details of the summarized embodiments of the
invention and/or additional embodiments of the invention may be
found in the Detailed Description of the Invention below.
[0015] A brief abstract of the technical disclosure in the
specification is provided as well only for the purposes of
complying with 37 C.F.R. 1.72. The abstract is not intended to be
used for interpreting the scope of the claims.
BRIEF SUMMARY OF THE INVENTION
[0016] The present invention addresses limitations of prior tube
machining systems by providing a novel rotary assembly having a
substantially lower mass and more efficient design than previous
designs.
[0017] The present invention is directed to several embodiments. In
at least one embodiment the invention is directed to a rotary drive
assembly having a fluid delivery tubes or lumen for actuating a
tube gripping collet or other retaining mechanism. In at least one
embodiment, the rotary shaft of the motor or other rotary apparatus
is machined or manufactured to include one or more fluid delivery
tubes extending longitudinally through the shaft wall. In use,
fluid is delivered from a first stationary stage of the apparatus
through a rotatable second stage and then servo coupling connection
into the shaft. At the distal end of the shaft the tubes are in
fluid communication with a collet. Fluid is delivered through the
tubes to actuate the collet or other gripping mechanism(s), the
actuated gripping mechanism(s) retain an end of a tube that is to
be rotated during stent processing by a laser or other etching or
cutting device(s).
[0018] In at least one embodiment the drive assembly includes a
head stock that includes a piston mechanism for opening and closing
(actuating) the collet or other gripping mechanism. The piston
mechanism is in fluid communication with the fluid delivery tubes
and is actuated by fluid flow therefrom.
[0019] In at least one embodiment the collet or gripping mechanism
is constructed and arranged to be longitudinally driven by the
fluid flow to engage the end of a tubular member.
[0020] In at least one embodiment the gripping mechanism is an
actuating collet, iris, chuck, touhy-borst, elastomer-clamping
device or any other device or mechanism that is fluid actuatable
for removably engaging a tubular member.
[0021] In some embodiments the tubular member is a, member suitable
for use in the construction of a stent. In at least one embodiment
the tubular member may be a member suitable for use in the
construction of a catheter or a component thereof.
[0022] In at least one embodiment the tubular member is disposed
about a mandrel, wherein the mandrel provides the tubular member
with internal support to prevent damage to the tubular member when
it is engaged by the gripping mechanism.
[0023] In at least one embodiment the rotary shaft of the drive
assembly defines a central lumen for transmitting fluid through the
drive assembly wherein the fluid is allowed to pass through and/or
around the tubular member engaged to the gripping mechanism.
[0024] These and other embodiments which characterize the invention
are pointed out with particularity in the claims annexed hereto and
forming a part hereof. However, for a better understanding of the
invention, its advantages and objectives obtained by its use,
reference should be made to the drawings which form a further part
hereof and the accompanying descriptive matter, in which there is
illustrated and described embodiments of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0025] A detailed description of the invention is hereafter
described with specific reference being made to the drawings.
[0026] FIG. 1 is a perspective view of an embodiment of the
invention.
[0027] FIG. 2 is a side view of the embodiment shown in FIG. 1.
[0028] FIG. 3 is a cross-sectional side view of the embodiment
shown in FIG. 2.
[0029] FIGS. 4 and 5 are detailed sectional views of the embodiment
shown in FIG. 3 illustrating the prospective flow path for the
collet actuating fluid.
DETAILED DESCRIPTION OF THE INVENTION
[0030] While this invention may be embodied in many different
forms, there are described in detail herein specific preferred
embodiments of the invention. This description is an
exemplification of the principles of the invention and is not
intended to limit the invention to the particular embodiments
illustrated.
[0031] For the purposes of this disclosure, like reference numerals
in the figures shall refer to like features unless otherwise
indicated.
[0032] As indicated above, the present invention may be embodied in
several forms. For example, in FIG. 1 an embodiment of the
invention is shown that comprises a rotary assembly, indicated
generally at 10, for use in cutting, etching, or otherwise
processing a tubular member 12.
[0033] Rotary assembly 10 comprises a rotary shaft 14, which at its
distal end 16 includes a gripping mechanism 18 that is configured
to removably engage at least a portion of the tubular member
12.
[0034] In use, rotary assembly 10 acts to grip and rotate the
tubular member 12 in a desired manner during the machining process
of the tubular member 12.
[0035] Typically, tubular member 12 is a hollow tubular member of
at least partial metallic composition such as may be suitable for
use in the construction of a stent, stent-graft, graft, vena-cava
filter or other implantable medical device. In some embodiments the
tubular member 12 may be constructed in whole or in part of one or
more polymer materials. In these later embodiments the tubular
member 12 may be suitable for use in the manufacture of stents and
other implantable medical devices, hypo-tubes, catheter shafts,
sleeves, and/or other catheter components.
[0036] Typically rotary assembly 10 is used in conjunction with, or
is apart of a system for cutting or otherwise machining or
processing the tubular member 12. For example, in a stent
manufacturing process a laser or other cutting mechanism is used to
cut or etch a pattern of one or more indentations or holes into the
tubular member 12. The rotary assembly 10 retains and rotates the
tubular member 12 relative to the cutting mechanism permitting cuts
to be made according to a predetermined pattern.
[0037] In the embodiments described herein the gripping mechanism
18 may be any type of gripping mechanism, including but not limited
to: a collet, iris, chuck, touhy-borst, elastomer-clamping device,
etc. The gripping mechanism 18 is engaged to the distal end 16 of
the rotary shaft 14 as is shown in FIGS. 1-3 and 5.
[0038] In the embodiments shown wherein, the gripping mechanism 18
is actuatable between a closed gripping position, wherein at least
a portion of the tubular member 12 is retained, and an open
gripping position, shown in FIG. 3, wherein the tubular member 12
is released.
[0039] The particular mechanism that the assembly 10 employs to
actuate the gripping mechanism 18 is a piston 20 or other fluid
driven mechanism that actuates longitudinally to the closed
position when fluid is applied to the piston 20. The gripping
mechanism is moved to the open position when fluid pressure is
removed, thereby allowing the piston 20 and gripping mechanism 18
to actuate back toward the shaft 14 thereby releasing the tubular
member 12.
[0040] Fluid, indicated by arrow 22 as shown in FIGS. 4 and 5, is
transmitted to the piston 20 through a unique series of connected
passages defining a fluid circuit 40 such as is described
below.
[0041] Fluid 22 may be any type of fluid suitable for performing
pneumatic or any other type of actuation. For example, fluid 22 may
be a gas such as air, oxygen, CO.sub.2, etc. In some embodiments
fluid 22 may be a liquid such as water, hydraulic fluid, oil, or
any other solution, mixture, or composition.
[0042] In the embodiments shown in the various FIGS. 1-5, the
assembly 10 may be considered as having two primary regions or
stages. The first stage 30 defines the fixedly mounted components
of the assembly 10, and the second stage 50 are those
interconnected components that are moveable relative to the first
stage 30.
[0043] First stage 30 includes a fluid input 32 for injecting
water, air or other fluid, indicated by arrow 34, into a jacket 36.
Fluid 34 may be the same or different as fluid 22. Fluid 34 acts to
cool the assembly 10 and may be used to aid in the processing of
the tubular member 12.
[0044] First stage 30, further includes a housing 31 to which an
input fitting 37 and an output fitting 38 are attached. Input
fitting 37 defines the initial portion of the circuit 40, wherein
fluid 22 is initially injected into the assembly 10. Likewise,
output fitting 38 defines the end of lumen circuit 40, wherein
fluid 22 leaves the assembly 10.
[0045] As indicated above, first stage 30 is stationary relative to
the second stage 50, second stage 50 is engaged to the rotary shaft
14 and rotates about the longitudinal axis 52 as shaft 14 is
rotated. Shaft 14 is rotated by a servo motor 42 which is disposed
about the shaft 14. An o-ring or other seal mechanism 44 separates
first stage 30 from second stage 50. However, the second stage 50,
employs a first input coupling 54 and a first output coupling 56
that further defines fluid circuit 40 and which are in fluid
communication with input fitting 37 and output fitting 38
respectively.
[0046] First input coupling 54 and first out put coupling 56 are
both distally engaged to the rotary shaft 14 at areas respectively
adjacent to the servo motor 42.
[0047] As is shown in FIG. 3, the rotary shaft 14 may be a solid or
hollow tube. In the embodiments shown, the shaft 14 is a hollow
tubular member having a central lumen 46 defined by a shaft wall
48. The shaft wall 48 includes a pair of longitudinal fluid
passageways 60 and 62 that further define circuit 40. First input
coupling 54 is engaged to passageway 60 and first output coupling
56 is engaged to passageway 62. By employing this unique
arrangement of components and passageways the rotary shaft 14 is
capable of transmitting fluid 22 longitudinally therethrough in two
directions simultaneously. Where shaft 14 is engaged to the second
stage 50 a second sealant mechanism 44 is employed to prevent loss
of fluid 22.
[0048] Where shaft 14 distally exits the servo motor 42, a portion
of the shaft 14 is engaged to a second input coupling 66 and a
second output coupling 68. The couplings 66 and 68 define lumens
that form part of circuit 40. The second input coupling 66 is
proximally engaged to the passage 60, whereas second output
coupling 68 is proximally engaged to the passage 62. An o-ring or
other sealant mechanism 44 prevents fluid loss.
[0049] As is shown in the various figures, particularly FIGS. 4 and
5, the fluid circuit 40 that is defined by the various fittings 37
and 38; couplings 54, 56, 66, and 68; and passageways 60 and 62 is
a continuous circuit of interconnected passageways or lumens that
allows fluid 22 to be transmitted through the assembly 10 to the
piston 20. When fluid is injected into the circuit 40 through the
input fitting 37, the fluid 22 is transmitted through the first
coupling 54, into passage 60 of the rotary shaft 14, and into the
second coupling 66. When the fluid 22 exits second coupling 66, the
fluid 22 will act upon piston 20 by pushing the piston in
longitudinally outward direction from the assembly 10, thereby
causing the gripping mechanism 18 to close about the tubular member
12. When the flow of fluid 22 to the piston 20 is interrupted, the
piston 20 moves longitudinally toward the assembly 10 to relax
gripping mechanism 18 and release the tubular member 12.
[0050] The above disclosure is intended to be illustrative and not
exhaustive. This description will suggest many variations and
alternatives to one of ordinary skill in this art. All these
alternatives and variations are intended to be included within the
scope of the claims where the term "comprising" means "including,
but not limited to". Those familiar with the art may recognize
other equivalents to the specific embodiments described herein
which equivalents are also intended to be encompassed by the
claims.
[0051] Further, the particular features presented in the dependent
claims can be combined with each other in other manners within the
scope of the invention such that the invention should be recognized
as also specifically directed to other embodiments having any other
possible combination of the features of the dependent claims. For
instance, for purposes of claim publication, any dependent claim
which follows should be taken as alternatively written in a
multiple dependent form from all prior claims which possess all
antecedents referenced in such dependent claim if such multiple
dependent format is an accepted format within the jurisdiction
(e.g. each claim depending directly from claim 1 should be
alternatively taken as depending from all previous claims). In
jurisdictions where multiple dependent claim formats are
restricted, the following dependent claims should each be also
taken as alternatively written in each singly dependent claim
format which creates a dependency from a prior
antecedent-possessing claim other than the specific claim listed in
such dependent claim below.
[0052] This completes the description of the preferred and
alternate embodiments of the invention. Those skilled in the art
may recognize other equivalents to the specific embodiment
described herein which equivalents are intended to be encompassed
by the claims attached hereto.
* * * * *