U.S. patent application number 10/359447 was filed with the patent office on 2004-08-12 for needle bar driver assembly for a sewing machine.
Invention is credited to Block, Paul, Lydick, Michael.
Application Number | 20040154504 10/359447 |
Document ID | / |
Family ID | 32823812 |
Filed Date | 2004-08-12 |
United States Patent
Application |
20040154504 |
Kind Code |
A1 |
Block, Paul ; et
al. |
August 12, 2004 |
Needle bar driver assembly for a sewing machine
Abstract
There is provided a needle bar driver assembly for an overlock
sewing machine. The overlock sewing machine has a needle for
penetrating a material to be sewed, a needle bar for securing the
needle thereto, and a throat plate for allowing the needle to pass
there through. The needle bar driver assembly includes a needle bar
connecting link assembly for driving the needle bar. The needle bar
driver assembly further includes an oscillating needle bar driving
assembly for driving the needle bar connecting link assembly and
for raising said needle bar connecting link assembly such that the
needle is more than 18 mm above the throat plate.
Inventors: |
Block, Paul; (Nesconset,
NY) ; Lydick, Michael; (Medford, NY) |
Correspondence
Address: |
KEUSEY, TUTUNJIAN & BITETTO, P.C.
14 VANDERVENTER AVENUE, SUITE 128
PORT WASHINGTON
NY
11050
US
|
Family ID: |
32823812 |
Appl. No.: |
10/359447 |
Filed: |
February 6, 2003 |
Current U.S.
Class: |
112/221 |
Current CPC
Class: |
D05B 55/14 20130101 |
Class at
Publication: |
112/221 |
International
Class: |
D05B 069/00 |
Claims
What is claimed is:
1. A needle bar driver assembly for an overlock sewing machine
having a needle for penetrating a material to be sewed, a needle
bar for securing the needle thereto, and a throat plate for
allowing the needle to pass there through, the needle bar driver
assembly comprising: a needle bar connecting link assembly for
driving the needle bar; and an oscillating needle bar driving
assembly for driving the needle bar connecting link assembly and
for raising said needle bar connecting link assembly such that the
needle is more than 18 mm above the throat plate.
2. The needle bar driver assembly of claim 1, wherein the overlock
sewing machine further has a looper for manipulating a thread, and
said oscillating needle bar driving assembly drives the needle bar
connecting link assembly such that the needle is synchronized with
a timing of the looper.
3. A method for controlling a needle of an overlock sewing machine,
the needle for penetrating a material to be sewed, the overlock
sewing machine further including a needle bar for securing the
needle thereto, and a throat plate for allowing the needle to pass
there through, the method comprising the steps of: driving the
needle bar; and raising the needle bar such that the needle is more
than 18 mm above the throat plate.
4. The method of claim 3, wherein the overlock sewing machine
further comprises a looper for manipulating a thread, and said
driving step comprises the step of driving the needle bar in
synchronization with a timing of the looper such that the needle is
synchronized with the timing of the looper.
5. A needle bar driver assembly for an overlock sewing machine,
comprising: a needle bar connecting link assembly, for driving a
needle bar; and an oscillating multi-part needle bar driving
assembly, capable of being in a closed condition and an open
condition, for transferring oscillatory motion to said needle bar
connecting link assembly in the closed condition and for lifting
the needle bar connecting link assembly to extend an upper travel
limit of said needle bar connecting link assembly in the open
condition.
6. The needle bar driver assembly of claim 5, wherein said
oscillating multi-part driver bar assembly comprises an upper link,
an outer link, a coupling link, and a main beam, the upper link and
the outer link both rotatably coupled to the main beam, the outer
link further rotatably coupled to said needle bar connecting link
assembly, the upper link and the outer link further operatively
coupled together via the coupling link such that a position of the
outer link tracks the position of the upper link, said oscillating
multi-part driver bar assembly capable of being in the closed
condition corresponding to a closed position of the upper link with
respect to the main beam and capable of being in an open condition
corresponding to an open position of the upper link with respect to
the main beam.
7. The needle bar driver assembly of claim 6, wherein the upper
link and the outer link are operatively together by the coupling
link using a tongue and groove structure.
8. The needle bar driver assembly of claim 7, wherein the tongue
and groove structure is disposed between the coupling link and the
outer link.
9. The needle bar driver assembly of claim 5, further comprising:
an opposing spring, connected to the oscillating multi-part driver
bar assembly, for applying downward pressure to the oscillating
multi-part driver bar assembly to at least one of limit an upper
travel limit of the oscillating multi-part driver bar assembly,
encourage the oscillating multi-part driver bar assembly to rotate
back into the closed condition, and prevent the oscillating
multi-part driver bar assembly from locking in the open
condition.
10. The needle bar driver assembly of claim 5, further comprising
an actuator for alternately placing the oscillating multi-part
driver bar assembly into the open condition and the closed
condition.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to sewing machines
and, more particularly, to a needle bar driver assembly for a
sewing machine.
BACKGROUND OF THE INVENTION
[0002] Conventional sewing machines employ a solid driver bar that
drives the needle bars, and hence the needles, in an oscillating
motion. However, the use of a solid driver bar limits the upper
travel limit of the needle bars, and hence the needles, making it
difficult for an operator to insert and remove thick materials
during a sewing operation.
[0003] Accordingly, it would be desirable and highly advantageous
to have a needle bar driver assembly that extends the upper travel
limit of the needle bar, and hence the needles, to reduce the
difficulties associated with inserting and removing thick materials
during a sewing operation.
SUMMARY OF THE INVENTION
[0004] The problems stated above, as well as other related problems
of the prior art, are solved by the present invention, a needle bar
driver assembly for a sewing machine.
[0005] According to an aspect of the present invention, there is
provided a needle bar driver assembly for an overlock sewing
machine. The overlock sewing machine has a needle for penetrating a
material to be sewed, a needle bar for securing the needle thereto,
and a throat plate for allowing the needle to pass there through.
The needle bar driver assembly comprises a needle bar connecting
link assembly for driving the needle bar. The needle bar driver
assembly further comprises an oscillating needle bar driving
assembly for driving the needle bar connecting link assembly and
for raising said needle bar connecting link assembly such that the
needle is more than 18 mm above the throat plate.
[0006] According to another aspect of the present invention, there
is provided a method for controlling a needle of an overlock sewing
machine. The needle is for penetrating a material to be sewed. The
overlock sewing machine further includes a needle bar for securing
the needle thereto, and a throat plate for allowing the needle to
pass there through. The method comprises the steps of driving the
needle bar, and raising the needle bar such that the needle is more
than 18 mm above the throat plate.
[0007] These and other aspects, features and advantages of the
present invention will become apparent from the following detailed
description of preferred embodiments, which is to be read in
connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a diagram illustrating a needle bar driver
assembly 100 in a locked condition, according to an illustrative
embodiment of the present invention;
[0009] FIG. 2 is a diagram illustrating the interior of a needle
bar drive chamber 200 that includes the needle bar driver assembly
100 shown in FIG. 1, according to an illustrative embodiment of the
present invention;
[0010] FIGS. 3A-C are diagrams generally illustrating the unlocking
of the needle bar driving assembly 101 shown in FIG. 1, according
to an illustrative embodiment of the present invention; and
[0011] FIG. 4 is a diagram illustrating the needle bar driver
assembly 100 of FIG. 1 in an unlocked condition, according to an
illustrative embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The present invention is directed to a needle bar driver
assembly for a sewing machine. Advantageously, the present
inventions allows for thick, quilted materials to be sewn by
raising the upper travel limit of the needle and presser foot of
the sewing machine. The present invention accomplishes the
preceding without affecting (slowing down) the speed of the sewing
machine.
[0013] It is to be appreciated that the present invention is
directed to "overlock" types of sewing machines, which are also
referred to as, for example, "overedge", "overcast", "overhead",
and "serger" type sewing machines. For the purposes of the present
invention, it is presumed that a sewing machine to which the
present invention is to be applied includes or is adapted to be
able to include a presser foot assembly for raising and lowering a
presser foot, a looper for manipulating a thread, a needle for
penetrating a material to be sewed, and a throat plate for allowing
the needle to pass there through. The presser foot is for pressing
down on the material to be sewed.
[0014] In one embodiment of the present invention, the present
invention includes a needle bar for securing the needle thereto and
a needle bar connecting link assembly for driving the needle bar.
Moreover, the present invention includes an oscillating needle bar
driving assembly for driving the needle bar connecting link
assembly in synchronization with a timing of the looper and for
raising the needle bar connecting link assembly such that the
needle is more than 18 mm above the throat plate. A presser foot
assembly raises the presser foot a distance corresponding to the
distance at which the needle is raised. The correspondence between
the distances at which the needle and presser foot are lifted is
necessary to prevent the needle from sticking through the bottom
plane of the presser foot and tearing the material that is to be
sewed. It is to be appreciated that while a distance of more than
18 mm is used herein as the example distance from the needle and
presser foot to the throat plate, even greater distances (20, 22,
24, 27, 30, 40, and so forth) may be readily achieved by the
present invention as is apparent to one of ordinary skill in the
art given the teachings of the present invention provided
herein.
[0015] As is known, the presser foot assembly includes a presser
foot (also interchangeably referred to herein as "material clamp")
that is connected to a presser foot arm. The presser foot arm is
also connected to a carriage. The carriage is connected to a slide
or actuating cylinder. The slide is connected to a main casting
(main body) of the sewing machine. The preceding presser foot
assembly provides linear displacement of the presser foot. As is
also known, radial displacement of the presser foot may also be
employed. In the case of radial displacement, the carriage is
replaced by a pivot block to provide angular (radial) displacement
of the presser foot. The present invention may be used with the
preceding types or any type of presser foot assembly, while
maintaining the spirit and scope of the present invention.
[0016] More detailed descriptions of various aspects of the present
invention will now be given with respect to FIGS. 1-5 below.
[0017] FIG. 1 is a diagram illustrating a needle bar driver
assembly 100 in a locked condition, according to an illustrative
embodiment of the present invention. A driver bar assembly 101
(hereinafter interchangeably referred to as "4 bar assembly")
transfers oscillating motion from a main rocking shaft (not shown)
to needle bar connecting links 115, that in turn drive needle bars
120 (and, thus, needles 125) upwards and downwards at their
prescribed angle. It is to be appreciated that the prior art
employs a solid driver bar. In contrast, the present invention
breaks up the driver bar into a locking (and unlocking) 4 bar
linkage, that when unlocked, allows the upper most limit of needle
bars 120 and, hence, needles 125 coupled thereto, to be extended a
significant angular distance. This increased secondary lift
dramatically reduces the difficulties (and secondary consequences)
associated with inserting and removing the thick quilted materials
associated with this sewing operation. The 4 bar assembly 101
includes an upper link 102, a main beam 104, an outer link 106, and
a coupling link 108. It is to be appreciated that while the 4 bar
linkage described herein includes 4 bars, hence the name, more or
less than 4 bars may be employed, as contemplated by one of
ordinary skill in the related art, to lift the needles a greater
distance than that obtained by the prior art.
[0018] The opening of 4 bar assembly 101 is achieved through a
first actuating cylinder 130 (hereinafter interchangeably referred
to a "lifting cylinder") and associated lifting shelf 132 attached
to the end of a piston 135 movably disposed in lifting cylinder
130. The sewing machine is programmed to stop with the needles at
their highest angular position. At this time, when actuated by the
operator, the lifting shelf 132 is raised upwards, unlocking a
locking latch 141 and immediately following upper link 102 of the 4
bar assembly 101 (see FIG. 2). The locking latch 141 (hereinafter
also referred to as "latch") includes a top ledge 142 coupled to a
bottom catch 144 (hereinafter "catch") via an intermediate member
146. The locking latch 141 is coupled to upper link 102 via a
connecting member 199. However, in another embodiment of the
present invention, locking latch 141 is directly coupled to upper
link 102. Moreover, in yet another embodiment of the present
invention, the physical structure and function represented by
connecting member 199 may be incorporated into either locking latch
141 and/or upper link 102.
[0019] An opposing spring 155 and spring block 156 shown in FIG. 1
are described in detail below with respect to FIGS. 2 and 4.
[0020] FIG. 2 is a diagram illustrating the interior of a needle
bar drive chamber 200 that includes the needle bar driver assembly
100 shown in FIG. 1, according to an illustrative embodiment of the
present invention. Observe the now visible catch 144 of locking
latch 141 that once held upper link 102 of 4 bar assembly 101
locked downwards to main beam 104 of 4 bar assembly 101.
[0021] The spring block 156 is coupled to the needle bar drive
chamber 200 to provide a solid base from which opposing spring 155
can push away from. Needles 125 are shown coupled to needle bars
120.
[0022] FIGS. 3A-C are diagrams generally illustrating the unlocking
of the needle bar driving assembly 101 shown in FIG. 1, according
to an illustrative embodiment of the present invention. FIG. 4 is a
diagram illustrating the needle bar driver assembly 100 of FIG. 1
in an unlocked condition, according to an illustrative embodiment
of the present invention.
[0023] When lifting shelf 132 is raised, it first hits top ledge
142 of locking latch 141, relieving the spring pressure and
pivoting catch 144 to the left and upwards, away from main beam 104
of 4 bar assembly 101 (see FIG. 3A).
[0024] Once catch 144 is free, lifting shelf 132 continues to lift
upper link 102, breaking 4 bar assembly 101 open (see FIGS. 3B and
3C). Observe the open condition of assembly 101, and how the outer
most link 106 attached to needle bar connecting link 115 raises
needle bar connecting links 115 and needle bars 120 an additional
angular distance (see FIG. 4). The coupling link 108 operatively
couples upper link 102 to outer link 106, so that the lifting of
upper link 102 results in a corresponding lifting of outer link 106
away from main beam 104. Fully, upper link 102 and outer link 106
are operatively coupled together such that the position of outer
link 106 tracks the position of upper link 102. In the illustrative
embodiment of the present invention, a tongue and groove structure
is employed to provide positional tracking between outer link 106
and upper link 102. The tongue and groove structure is disposed
between coupling link 108 and outer link 106. As is known to one of
ordinary skill in the related art, the tongue portion and the
groove portion of the tongue and groove structure may be readily
disposed on coupling link 108 and outer link 106, respectively, or
vice versa, depending on, for example, the shape (e.g., concave,
convex) of the tongue portion. It is to be appreciated that while a
tongue and groove structure are described herein for enabling the
tracking of the outer link position to the upper link position,
other structures may be readily used to achieve the same position
tracking result as are readily contemplated by one of ordinary
skill in the related art, while maintaining the spirit and scope of
the present invention.
[0025] This motion is synchronized with the lifting of a material
clamp (not shown), allowing the operator to insert or remove the
material as needed. As long as the operator's foot is actuating the
sewing pedal backwards (not shown) the sewing machine will remain
in this condition.
[0026] The opposing spring 155 and spring block 156 apply pressure
to outer link 106 of 4 bar assembly 101, acing as a compressive
stop. This spring 155 will also encourage outer link 106 to rotate
back into its locked position, as well as prevent outer link 106
from over rotating and locking 4 bar assembly 101 in an "open"
condition.
[0027] A second actuating cylinder 160 (hereinafter interchangeably
referred to as locking cylinder) and its associated piston 165 are
shown in FIG. 4. When the operator releases the sewing pedal (not
shown), second actuating cylinder 160 actuates piston 165 downwards
to its lowest "docking" point. At this extent of its limit, lifting
shelf 132 will not interfere with oscillating 4 bar assembly
101.
[0028] The 4 bar assembly 101 would remain open, however, and
unlocked, if not for locking cylinder 160. When piston 165 of
locking cylinder 160 actuates downwards, piston 165 depresses the
top ledge 142 of the locking latch 141, and consequently, upper bar
102 of 4 bar assembly 101. Piston 165 continues to depress latch
141 until catch 144 locks beneath the lower plane of main beam 104
of 4 bar assembly 101. This actuation is momentary, releasing and
raising upwards (and remaining there) fractions of a second after
it locks the mechanism. When 4 bar assembly 101 is locked, and
locking cylinder 160 is fully retracted, the sewing machine
operator proceeds and runs the machine through its cycle. The 4 bar
driving assembly 101 remains locked until the unit stops and
performs its lifting cycle once again.
[0029] Although the illustrative embodiments have been described
herein with reference to the accompanying drawings, it is to be
understood that the present invention is not limited to those
precise embodiments, and that various other changes and
modifications may be affected therein by one of ordinary skill in
the related art without departing from the scope or spirit of the
invention. All such changes and modifications are intended to be
included within the scope of the invention as defined by the
appended claims.
* * * * *