U.S. patent application number 13/106425 was filed with the patent office on 2011-12-01 for sewing machine.
This patent application is currently assigned to AISIN SEIKI KABUSHIKI KAISHA. Invention is credited to Yasunori KAWAI.
Application Number | 20110290168 13/106425 |
Document ID | / |
Family ID | 44561362 |
Filed Date | 2011-12-01 |
United States Patent
Application |
20110290168 |
Kind Code |
A1 |
KAWAI; Yasunori |
December 1, 2011 |
SEWING MACHINE
Abstract
A sewing machine includes a main body, a presser bar attached to
the main body so as to move along a vertical direction of the
sewing machine and detachably holding a presser foot, a needle
thread tension adjustment mechanism selectively brought into
inactive and active modes, the needle thread tension adjustment
mechanism releasing a needle thread tension in the inactive mode
and maintaining the needle thread tension in the active mode, and a
presser bar lifting lever manually rotated along the vertical
direction by a user of the sewing machine and adjusting a position
of the presser bar in the vertical direction in accordance with the
manual rotation, the presser bar lifting lever including a height
adjustment cam portion adjusting the position of the presser bar in
the vertical direction and a thread tension adjustment cam portion
allowing the needle thread tension adjustment mechanism to adjust
the needle thread tension.
Inventors: |
KAWAI; Yasunori;
(Nagoya-shi, JP) |
Assignee: |
AISIN SEIKI KABUSHIKI
KAISHA
Kariya-shi
JP
|
Family ID: |
44561362 |
Appl. No.: |
13/106425 |
Filed: |
May 12, 2011 |
Current U.S.
Class: |
112/236 ;
112/237; 112/239 |
Current CPC
Class: |
D05B 29/12 20130101;
D05B 29/06 20130101; D05B 47/00 20130101 |
Class at
Publication: |
112/236 ;
112/237; 112/239 |
International
Class: |
D05B 29/02 20060101
D05B029/02 |
Foreign Application Data
Date |
Code |
Application Number |
May 28, 2010 |
JP |
2010-122992 |
Claims
1. A sewing machine, comprising: a main body; a presser bar
attached to the main body so as to move along a vertical direction
of the sewing machine and detachably holding a presser foot at a
lower end; a needle thread tension adjustment mechanism selectively
brought into inactive and active modes, the needle thread tension
adjustment mechanism releasing a needle thread tension in the
inactive mode and maintaining the needle thread tension in the
active mode; and a presser bar lifting lever mounted to the main
body for rotation about a rotary shaft along the vertical direction
of the main body, the presser bar lifting lever including a height
adjustment cam portion adjusting the position of the presser bar in
the vertical direction and a thread tension adjustment cam portion
allowing the needle thread tension adjustment mechanism to adjust
the needle thread tension, wherein the height adjustment cam
portion of the presser bar lifting lever includes a cam profile
arranging the presser bar in a lower position in which the sewing
machine is operable in a normal sewing mode, the cam profile of the
height adjustment cam portion allowing the presser bar to be
maintained in a first higher holding position to which the presser
bar is moved further upward from the lower position in the vertical
direction, the cam profile of the height adjustment cam portion
allowing the presser bar to be maintained in a second higher
holding position to which the presser bar is moved further upward
from the first holding position in the vertical direction, and
wherein the thread tension adjustment cam portion of the presser
bar lifting lever includes a cam profile bringing the needle thread
tension adjustment mechanism into the active mode when the presser
bar is in the lower position, the cam profile of the thread tension
adjustment cam portion bringing the needle thread tension
adjustment mechanism into the inactive mode when the presser bar is
in the first higher holding position, the cam profile of the thread
tension adjustment cam portion bringing the needle thread tension
adjustment mechanism into the active mode when the presser bar is
in the second higher holding position.
2. The sewing machine according to claim 1, wherein the presser bar
includes a presser bar holding member supported by the presser bar,
and wherein the cam profile of the height adjustment cam portion of
the presser bar lifting lever comprises: a first cam surface being
in contact with the presser bar holding member at an upper side of
the rotary shaft and positioned on a straight line when the presser
bar is in the first holding position, the straight line passing
through a central axis of the rotary shaft so as to be
perpendicular to the central axis; and a second cam surface being
in contact with the presser bar holding member at the upper side of
the rotary shaft and positioned on the straight line when the
presser bar is in the second holding position.
3. The sewing machine according to claim 2, wherein the first cam
surface of the cam profile of the height adjustment cam portion
extends along a horizontal direction of the sewing machine when the
presser bar is in the first holding position, and the second cam
surface of the cam profile of the height adjustment cam portion
extends along the horizontal direction of the sewing machine.
4. The sewing machine according to claim 1, further comprising a
switch detecting the lower position, the first holding position,
and the second holding position of the presser bar.
5. The sewing machine according to claim 4, further comprising a
switch lever rotating along with the rotation of the presser bar
lifting lever, wherein the switch outputs a first ON signal when
detecting that the switch lever is rotated in a first direction,
the switch outputting an OFF signal when detecting that the switch
lever is rotated to an intermediate position, the switch outputting
a second ON signal when detecting that the switch lever is rotated
in a second direction, and wherein the sewing machine is operable
in the normal sewing mode when the lower position of the switch
lever is determined on the basis of the first ON signal outputted
from the switch, the sewing machine is not operable in the normal
sewing mode when the first holding position of the switch lever is
determined on the basis of the OFF signal outputted from the
switch, and the sewing machine is operable in the normal sewing
mode when the second holding position of the switch lever is
determined on the basis of the second ON signal outputted from the
switch.
6. The sewing machine according to claim 1, further comprising an
embroidery restriction member attached to the main body, the
embroidery restriction member making contact with either one of the
presser foot and a holder for attaching the presser foot to the
presser bar, and restricting the presser bar from shifting to the
second holding position in a state where the presser foot is
attached to the presser bar.
7. The sewing machine according to claim 1, further comprising: a
thread tension releasing operation member selectively bringing the
needle thread tension adjustment mechanism into the inactive and
active modes; a rod engaged with the thread tension releasing
operation member; a motor electrically operating the thread tension
releasing operation member and the rod to bring the needle thread
tension adjustment mechanism into the inactive mode; and a thread
tension releasing portion operating the thread tension releasing
operation member in accordance with the manual rotation of the
presser bar lifting lever by the user of the sewing machine to
bring the needle thread tension adjustment mechanism into the
inactive mode, wherein the thread tension releasing operation
member includes a protruding portion and the rod includes an
elongated bore having a free space to which the protruding portion
of the thread tension releasing operation member is fitted, the
elongated bore being larger in size than the protruding portion,
and wherein when the motor is driven in a direction to move the rod
in a thread tension releasing direction, the thread tension
releasing operation member is moved via the protruding portion by
the rod to bring the needle thread tension adjustment mechanism
into the inactive mode.
8. The sewing machine according to claim 7, wherein when the
presser bar lifting lever is manually rotated by the user of the
sewing machine and the thread tension releasing operation member is
moved by the thread tension adjustment cam portion in the thread
tension releasing direction to bring the needle thread tension
adjustment mechanism into the inactive mode, the protruding portion
moves in the elongated bore therealong and the free space of the
elongated bore prevents the movement of the thread tension
releasing operation member from being transmitted to the rod.
9. A sewing machine, comprising: a main body; a presser bar
attached to the main body for movement along a vertical direction
of the main body and having a lower end to which a presser foot is
detachably connected; a needle thread tension adjustment mechanism
configured to, when being in its inactive and active modes,
releasing and maintaining a needle thread tension, respectively;
and a presser bar lifting lever pivoted to the main body via a
rotary shaft for manual rotational movement along the vertical
direction of the main body, the presser bar lifting lever including
a height adjustment cam portion for adjusting a height of the
presser bar upon the manual rotational movement of the presser bar
lifting lever and a thread tension adjustment cam portion for
adjusting the needle thread tension, wherein the height adjustment
cam portion of the presser bar lifting lever has a cam profile
which allows the presser bar to locate at selective one of a lower
position for a normal sewing mode, a first higher holding position
having a higher elevation than the lower position, and a second
higher holding position having a higher elevation than the first
higher holding position, and wherein the thread tension adjustment
cam portion has a cam profile which causes the needle thread
tension adjustment mechanism to operate in the active mode, the
inactive mode, and the active mode, when the presser bar locates at
the low position, the first holding position, and the second
holding position, respectively.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority under 35
U.S.C. .sctn.119 to Japanese Patent Application 2010-122992, filed
on May 28, 2010, the entire content of which is incorporated herein
by reference.
TECHNICAL FIELD
[0002] This disclosure relates to a sewing machine having a presser
bar vertically movable and holding a presser foot.
BACKGROUND DISCUSSION
[0003] A known presser bar lifting mechanism for a sewing machine
disclosed in JP2001-190878A (hereinafter referred to as Reference
1) includes a control unit and a solenoid that moves a presser foot
upward, which is consistently biased downward by a presser foot
spring. In the aforementioned configuration of the presser bar
lifting mechanism, the control unit controls an absorbing force of
the solenoid to thereby enable a user of the sewing machine to hold
the presser foot in uppermost and intermediate position that is
located between the uppermost position and a lowermost position in
a vertical direction of the sewing machine.
[0004] A known embroidery presser (darning presser) for an
embroidery machine is disclosed in JP 2006-263170A (hereinafter
referred to as Reference 2). A pivot lever lifting up a presser
foot of the embroidery presser is attached to the embroidery
presser. The pivot lever moves the presser foot upward in
accordance with an upward movement of a presser lifting operation
lever. For example, when a user of the embroidery machine moves the
embroidery presser upward, the presser foot of the embroidery
presser moves further upward than a holder detachably attached to a
lower end of a presser bar. Accordingly, a distance between a
needle plate and the presser foot in a vertical direction of the
embroidery machine increases; therefore, an embroidery frame may be
easily detached from an embroidery frame transferring device.
[0005] A sewing machine and a presser foot bar lifting device for
the same are disclosed in JP2009-112325A (hereinafter referred to
as Reference 3). According to the sewing machine and the presser
foot bar lifting device for the same of Reference 3, a presser foot
lifting lever may rotate from an axial direction of a presser bar
toward a right side in a horizontal direction seen from a user of
the sewing machine and toward a rear side in a longitudinal
direction seen from the user of the sewing machine. Accordingly,
when moving the presser foot lifting lever upward and downward, the
user of the sewing machine may rotate the presser foot lifting
lever toward the right side and the rear side depending on his/her
using conditions of the sewing machine. Consequently, when the user
of the sewing machine sews a workpiece fabric by means of the
sewing machine, the presser foot lifting lever does not interfere
with the workpiece fabric. In addition, the operability of the
presser bar lifting lever may not deteriorate.
[0006] According to the presser bar lifting mechanism described in
Reference 1, the solenoid is utilized to the sewing machine in
order to move the presser foot and the presser bar upward.
Accordingly, for example, when the sewing machine is switched off,
the presser foot and the presser bar are not maintained in the
respective upward positions and are moved downward by the biasing
force of the presser foot spring. In addition, the solenoid and the
control unit are utilized in the sewing machine in order to move
the presser foot and the presser bar upward, therefore increasing
the cost of the sewing machine compared to a domestic manual sewing
machine including a manual operated presser bar lifting lever.
[0007] According to the presser foot described in Reference 2, in a
condition where the presser lifting operation lever is moved upward
by the user of the embroidery machine (in a condition where the
user of the embroidery machine attaches and detaches the embroidery
frame to and from the embroidery frame transferring device), the
embroidery frame and the presser foot of the embroidery presser do
not make contact with each other in the vertical direction.
However, when the presser lifting operation lever is moved downward
in a condition where the user of the embroidery machine does
embroidery by means of the embroidery machine, the embroidery frame
and the presser foot may make contact with each other. In addition,
the user of the embroidery machine may do embroidery by not using
the presser foot but by using the embroidery frame only. However,
according to the embroidery machine of Reference 2, even in a case
where the user does embroidery by not using the presser foot but by
using the embroidery frame, the embroidery frame and the presser
bar may make contact with each other in the vertical direction.
[0008] According to Reference 3, in a case where the user of the
sewing machine uses an embroidery frame when doing freehand
embroidery by means of the sewing machine, the presser foot lifting
lever does not make contact with the embroidery frame in a vertical
direction of the sewing machine while the presser bar (from which
the presser foot is detached) may make contact with the embroidery
frame. Further, the presser foot lifting lever does not include a
cam adjusting an opening angle between a pair of thread tension
disks. In addition, the cam adjusting the opening angle between the
pair of thread tension disks rotates about an axis of the presser
bar; therefore, it is difficult for such cam to be arranged at the
presser foot lifting lever. As a result, the presser foot bar
lifting device configured at low cost may not allow the presser bar
lifting lever to operate in synchronization with the adjustment of
the opening angle between the pair of thread tension disks.
[0009] A need thus exists for a sewing machine which is not
susceptible to the drawback mentioned above.
SUMMARY
[0010] According to an aspect of this disclosure, a sewing machine
includes a main body, a presser bar attached to the main body so as
to move along a vertical direction of the sewing machine and
detachably holding a presser foot at a lower end, a needle thread
tension adjustment mechanism selectively brought into inactive and
active modes, the needle thread tension adjustment mechanism
releasing a needle thread tension in the inactive mode and
maintaining the needle thread tension in the active mode, and a
presser bar lifting lever manually rotated about a rotary shaft
along the vertical direction by a user of the sewing machine and
provided so as to adjust a position of the presser bar in the
vertical direction in accordance with the manual rotation, the
presser bar lifting lever including a height adjustment cam portion
adjusting the position of the presser bar in the vertical direction
and a thread tension adjustment cam portion allowing the needle
thread tension adjustment mechanism to adjust the needle thread
tension, wherein the height adjustment cam portion of the presser
bar lifting lever includes a cam profile arranging the presser bar
in a lower position in which the sewing machine is operable in a
normal sewing mode, the cam profile of the height adjustment cam
portion allowing the presser bar to be maintained in a first
holding position to which the presser bar is moved further upward
from the lower position in the vertical direction, the cam profile
of the height adjustment cam portion allowing the presser bar to be
maintained in a second holding position to which the presser bar is
moved further upward from the first holding position in the
vertical direction, and wherein the thread tension adjustment cam
portion of the presser bar lifting lever includes a cam profile
bringing the needle thread tension adjustment mechanism into the
active mode when the presser bar is in the lower position, the cam
profile of the thread tension adjustment cam portion bringing the
needle thread tension adjustment mechanism into the inactive mode
when the presser bar is in the first holding position, the cam
profile of the thread tension adjustment cam portion bringing the
needle thread tension adjustment mechanism into the active mode
when the presser bar is in the second holding position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The foregoing and additional features and characteristics of
this disclosure will become more apparent from the following
detailed description considered with the reference to the
accompanying drawings, wherein:
[0012] FIG. 1 is a front perspective view of a main portion of a
computerized sewing machine according to an embodiment disclosed
here;
[0013] FIG. 2 is a rear perspective view of the main portion of the
computerized sewing machine according to the embodiment disclosed
here;
[0014] FIG. 3 is a perspective view of a lock mechanism of a
presser bar lifting lever holding a presser bar in first and second
holding positions at an upper side of a needle plate;
[0015] FIG. 4A is a side view illustrating a condition where a
presser bar lifting lever of a known sewing machine is in a lower
position;
[0016] FIG. 4B is a side view illustrating a condition where the
presser bar lifting lever of the known sewing machine holds a
presser bar in a first holding position;
[0017] FIG. 4C is a side view illustrating a condition where the
presser bar lifting lever of the known sewing machine holds the
presser bar in a position located further upward than the first
holding position;
[0018] FIG. 5 is a perspective view of the presser bar lifting
lever of the known sewing machine;
[0019] FIG. 6A is an explanation diagram describing a movement of a
pair of thread tension disks of the sewing machine according to the
embodiment;
[0020] FIG. 6B is an explanation diagram describing the movement of
the pair of thread tension disks of the sewing machine according to
the embodiment;
[0021] FIG. 7A is a side view illustrating a condition where the
presser bar lifting lever of the sewing machine according to the
embodiment disclosed here holds the presser bar in a lower
position;
[0022] FIG. 7B is a side view illustrating a condition where the
presser bar lifting lever of the sewing machine according to the
embodiment disclosed here holds the presser bar in the first
holding position;
[0023] FIG. 7C is a side view illustrating a condition where the
presser bar lifting lever of the sewing machine according to the
embodiment disclosed here holds the presser bar in the second
holding position;
[0024] FIG. 8 is a perspective view of the presser bar lifting
lever of the sewing machine according to the embodiment disclosed
here;
[0025] FIG. 9 is an explanation diagram describing a condition
where a thread tension adjustment cam portion of the presser bar
lifting lever and a thread tension releasing portion are in contact
with each other;
[0026] FIG. 10A is a side view explaining a detecting function of a
switch and illustrating a positional relation between a switch
lever and a leaf switch of the switch when the presser bar lifting
lever is in the lower position;
[0027] FIG. 10B is a side view explaining the detecting function of
the switch and illustrating the positional relation between the
switch lever and the leaf switch of the switch when the presser bar
lifting lever is lever is in the first holding position;
[0028] FIG. 10C is a side view explaining the detecting function of
the switch and illustrating the positional relation between the
switch lever and the leaf switch of the switch when the presser bar
lifting lever is in the second holding position;
[0029] FIG. 11 is a graph illustrating a relation between an
rotation angle of the presser bar lifting lever and a vertical
movement distance of the presser bar and a relation between the
rotation angle of the presser bar lifting lever and an opening
angle between the pair of thread tension disks;
[0030] FIG. 12A is an explanation drawing describing a function of
a stopper and illustrating the stopper under a condition where the
presser foot is attached to the presser bar;
[0031] FIG. 12B is an explanation drawing describing the function
of the stopper and illustrating the stopper under a condition where
the presser foot is detached from the presser bar; and
[0032] FIG. 13 is an explanation diagram illustrating a rod
operable together with an automatic thread tension disk
opening/closing mechanism.
DETAILED DESCRIPTION
[0033] An embodiment of this disclosure will be explained with
reference to illustrations of the accompanying drawings as follows.
Vertical, longitudinal, and horizontal directions described herein
will correspond to vertical (upper and lower sides), longitudinal
(forward and rear sides), and horizontal directions (right and left
sides) of a computerized sewing machine (sewing machine) according
to the embodiment unless otherwise specified. FIGS. 1 to 3
illustrate a condition where a presser bar lifting lever 3 for a
presser bar 5 of the sewing machine according to the embodiment is
attached to a main body 1 of the sewing machine. As illustrated in
FIG. 3, the presser bar lifting lever 3 has a lock mechanism to
hold or lock the presser bar 5 in two positions (first and second
holding positions (see FIGS. 7A and 7B). As shown in FIGS. 1 and 2,
the main body 1 includes a needle bar 51 to which a sewing needle
50 is attached. As illustrated in FIG. 3, the presser bar lifting
lever 3 includes an operation portion 3w manually rotated by a user
of the sewing machine. Further, the presser bar lifting lever 3 is
attached to a rotary shaft 1c extending forward from the main body
1 in the longitudinal direction, thereby being movable along a
vertical direction of the main body 1. A thread tension releasing
portion 23 having an arm shape is attached to the main body 1 by a
retaining ring 24 so as to be rotate about a shaft 1b. The thread
tension releasing portion 23 will be hereinafter referred to as a
thread tension releasing arm 23. The thread tension releasing arm
23 transmits a lift amount of a height adjustment cam portion 3H of
the presser bar lifting lever 3 to a thread tension releasing
operation member 12. The thread tension releasing arm 23 includes a
contact portion 23b at an upper end. As illustrated in FIGS. 1 and
13, the thread tension releasing operation member 12 having an arm
shape and transmitting the rotation of the thread tension releasing
arm 23 to a needle thread tension adjustment mechanism 9 is
attached to the main body 1 by a retaining ring 32r so as to be
rotate about a shaft 1a along the horizontal direction of the
sewing machine, i.e. along thread tension releasing directions
indicated by arrows X5 and X6 in the horizontal direction. As
illustrated in FIG. 2, a pair of thread tension disks 13b and 13c
(first and second thread tension disks) of the needle thread
tension adjustment mechanism 9 is located in adjacent to a contact
portion 12a at a first end of the thread tension releasing
operation member 12.
[0034] As seen from FIGS. 6A and 6B, the thread tension releasing
operation member 12 is pressed by the contact portion 23b of the
thread tension releasing arm 23 and thereby rotates about the shaft
1a by a rotation angle E1 in thread tension releasing directions
indicated by arrows X5 and X6. Then, the rotating operation of the
thread tension releasing arm 23 is transmitted to the first thread
tension disk 13b, which is adjacent to the thread tension releasing
operation member 12, therefore separating the first thread tension
disk 13b from the second thread tension disk 13c and moving the
first thread tension disk 13b in a direction indicated by an arrow
X7 corresponding to a thread tension releasing direction. As
illustrated in FIG. 2, a return spring 14 for returning the thread
tension releasing operation member 12 to an initial position is
hooked at a second end of the thread tension releasing operation
member 12. The contact portion 12a of the thread tension releasing
operation member 12 is biased by a biasing force of the return
spring 14 in a direction in which the contact portion 12a separates
from the first thread tension disk 13b (the direction is an
opposite direction from the thread tension releasing direction of
the arrow X6).
[0035] As illustrated in FIG. 3, the presser bar 5 extending in the
vertical direction is attached to the main body 1 by a bearing
support plate 28 and a bolt 27 while penetrating through a
spherical bearing 29 along the vertical direction. A presser bar
holding member 20 including a contact portion 20c is fixed to the
presser bar 5 by means of a screw 21. A presser spring 22 and a
presser bar support plate 25 are attached to an upper portion of
the presser bar 5. The presser bar support plate 25 is fixed to the
main body 1 by means of a screw 26. In a condition where the
presser bar support plate 25 is fixed to the main body 1 by the
screw 26, the contact portion 20c of the presser bar holding member
20 fixed to the presser bar 5 so as to be integrated therewith is
biased in a downward direction (indicated by an arrow Y2 in FIG. 3)
by a biasing force of the presser spring 22. Thus, the contact
portion 20c of the presser bar holding member 20 is contactable
with first and second cam surfaces 3c and 3d of the height
adjustment cam portion 3H of the presser bar lifting lever 3 as
will be described below.
[0036] As seen from FIG. 3, the sewing machine includes a presser
foot 6 utilized to press a workpiece fabric from an upper side of
the presser bar 5 relative to a needle plate 2 when the sewing
machine operates in a normal sewing mode. A holder 4 combined with
the presser foot 6 is detachably fixed to a lower end 5d of the
presser bar 5 by means of a screw 34. For example, when the screw
34 is removed from the presser bar 5, the presser foot 6 and the
holder 4 may be detached from the presser bar 5. For instance, in a
case of the embroidery, the freehand embroidery, or the like, the
user of the sewing machine removes the presser foot 6 and the
holder 4 from the presser bar 5. Such procedures are conducted in
order to avoid interference between an embroidery frame and the
presser foot 6. In addition, as seen from FIG. 3, an external
thread is formed at an upper portion of a stopper 7 (embroidery
restriction member) extending in the vertical direction and having
a shaft shape. An upper end of the stopper 7 is fixed to the main
body 1 by means of an adjustment nut 35 while the external thread
of the stopper 7 is screwed with an internal thread at a lower
surface 1u of the main body 1 (see FIGS. 12A and 12B). The stopper
7 is rotated about an axis while meshing with the internal thread
of the lower surface 1u of the main body 1 along the vertical
direction; thereby, a length of the stopper 7 protruding downward
from the lower surface 1u of the main body 1 in the vertical
direction may be adjusted (the length of the stopper 7 corresponds
to a distance LA between a lower end 7a of the stopper 7 and an
upper surface 4a of the holder 4 illustrated in FIG. 1).
[0037] As seen from FIG. 3, a leaf switch 18 having an intermediate
contact point 18a is fixed to a switch base 16 by means of a screw
33. The leaf switch 18, a switch lever 15, the switch base 16 that
constitutes a portion of a switch unit are attached to one another.
A switch is formed by the leaf switch 18, the switch lever 15, and
the switch base 16. The switch lever 15 is attached to the main
body 1 so as to rotate about a shaft 16a of the switch base 16 in a
condition where the switch lever spring 17 formed by a torsion coil
spring having first and second arms for returning the switch lever
15 to an initial position is arranged between the switch lever 15
and the switch base 16. The first arm of the switch lever spring 17
is hooked to the switch base 16 while the second arm of the switch
lever spring 17 is hooked to the switch lever 15; thereby, the
switch lever 15 is biased in a first direction indicated by an
arrow R2 shown in FIG. 3 and corresponding to a clockwise direction
in FIG. 3. The switch unit attached to the switch base 16 is fixed
to a back surface of the main body 1 by means of a screw 19. As
illustrated in FIG. 3, the switch lever 15 includes an operation
bore 15a having an elongated shape. A switch lever operation arm 3f
of the presser bar lifting lever 3 is fitted to the operation bore
15a (see FIGS. 8 and 10); thereby, the switch lever 15 rotates
along with the presser bar lifting lever 3. In other words, when
the presser bar lifting lever 3 is rotatably operated about the
rotary shaft 1c, the switch lever 15 rotates in the same direction
as the presser bar lifting lever 3 rotates. In addition, as
illustrated in conditions (a), (b), and (c) of FIGS. 10A, 10B, and
100, the switch lever 15 includes first and second operation arms
15b and 15c facing each other so as to sandwich therebetween the
intermediate contact point 18a of the leaf switch 18. As in the
condition (b) of FIG. 10B, the first operation arm 15b and the
second operation arm 15c of the switch lever 15 are not in contact
with the intermediate contact point 18a of the leaf switch 18. In
addition, a switch including one circuit and two contact points
(the contact points are consistently opened) may be applied to the
aforementioned switch at which the switch lever 15 rotates along
with the rotation of the presser bar lifting lever 3. The switch
lever 15 may rotate in a clockwise or counterclockwise direction
and may move to an intermediate position in a movable range of the
switch lever. In such case, the switch may be configured to close
the contact portions (output three types of signals). A control
unit may include a program selecting a sewing pattern related only
to the normal sewing mode when the signal corresponding to the
clockwise or counterclockwise rotation of the switch lever 15 is
outputted. Further the program selects a sewing pattern related
only to an embroidery mode.
[0038] The sewing machine according to the embodiment is applied as
a sewing machine by which the user of the sewing machine may do
embroidery, freehand embroidery, or the like. Accordingly, as
illustrated in FIG. 1, in addition to components described above,
an automatic thread tension disk opening/closing mechanism 10 is
arranged on the sewing machine. The automatic thread tension disk
opening/closing mechanism 10 automatically releases a needle thread
tension by means of a motor 10c, for example, when the sewing
machine operates in the embroidery mode. A rod 11 is pulled in a
thread tension releasing direction (indicated by an arrow X5 in
FIG. 13) by an operating force of the motor 10c of the automatic
thread tension disk opening/closing mechanism 10 and the operating
force of the motor 10c is transmitted by the rod 11 to the thread
tension releasing operation member 12. Accordingly, the thread
tension releasing operation member 12 rotates about the rotary
shaft 1a by the rotation angle E1 toward the thread tension
releasing directions of the arrows X5 and X6 as seen in FIGS. 6A
and 6B; thereby, the first thread tension disk 13b separates from
the second thread tension disk 13c. As a result, the needle thread
tension adjustment mechanism 9 is brought into an inactive mode to
thereby loosen the needle thread tension.
[0039] FIGS. 4A, 4B, 4C, and 5 illustrate a mechanism of a presser
bar lifting lever 30 of a known sewing machine. As illustrated in
FIGS. 4A, 4B, 4C, and 5, the presser bar lifting lever 30
(corresponding to the presser bar lifting lever 3 in the
embodiment) and a thread tension releasing arm 31 (corresponding to
the thread tension releasing arm 23 in the embodiment) are applied
to the known sewing machine. As shown in FIG. 5, the presser bar
lifting lever 30 includes cam surfaces 30a and 30c for adjusting a
position of the presser bar lifting lever 30 in a vertical
direction of the known sewing machine, and a cam surface 30b for
adjusting a needle thread tension. Same numbers are applied to the
same components as those utilized in the sewing machine according
to the embodiment. As in a condition (a) illustrated in FIG. 4A,
when the presser bar lifting lever 30 is moved in a downward
direction (indicated by an arrow Y2) by a user of the know sewing
machine in a condition where the presser foot 6 is attached to the
presser bar 5, i.e. when the known sewing machine is operable in a
normal sewing mode, the presser bar 5 is biased by the biasing
force of the presser spring 22 toward the downward direction of the
arrow Y2 and the presser foot 6 is pressed against the needle plate
2. Accordingly, a clearance A4 is generated between the cam surface
30a of the presser bar lifting lever 30 and the presser bar holding
member 20, that is, the cam surface 30a of the presser bar lifting
lever 30 is not in contact with the presser bar holding member 20.
At this time, a lift amount of the cam surface 30b of the presser
bar lifting lever 30 may be transmitted by a contact portion 31b at
an upper end of the thread tension releasing arm 31, via a contact
portion 31a at a lower end of the tension releasing arm 31 making
contact with the presser bar lifting lever 30, to the thread
tension releasing operation member 12. At this time, a clearance D1
is generated (refer to a condition (a) illustrated in FIG. 6A)
between an operating point 13a of the first thread tension disk 13b
and the contact portion 12a of the thread tension releasing
operation member 12, which faces the first thread tension disk 13b.
Accordingly, the first thread tension disk 13b is closed relative
to the second thread tension disk 13c and the needle thread tension
adjustment mechanism 9 is brought into an active mode to thereby
maintain the needle thread tension. As a result, the known sewing
machine may be operated in the normal sewing mode by the user when
the presser bar lifting lever 30 is in the condition (a) of FIG.
4A.
[0040] According to the known sewing machine, the user rotates the
presser bar lifting lever 30 upward by a rotation angle B1 as the
condition (a) of FIG. 4A shifts to a condition (b) illustrated in
FIG. 4B. Then, the presser bar holding member 20 is lifted up by
the cam surface 30c of the presser bar lifting lever 30 in
accordance with a lift amount of the cam surface 30a of the presser
bar lifting lever 30, therefore moving the presser bar holding
member 20 and the presser bar 5 in an upward direction indicated by
an arrow Y1 in FIG. 4A. As illustrated in the condition (b) of FIG.
4B, an upper end of the presser bar 5 is moved upward by a distance
B2 from a position (lower position) in the condition (a) of FIG. 4A
to a first holding position in the condition (b) of FIG. 4B and is
maintained thereat. The presser foot 6 attached to the presser bar
5 is moved upward by the distance B2 in the same way as the presser
bar 5 is moved upward. In the condition (b) of FIG. 4B, the lift
amount of the cam surface 30b of the presser bar lifting lever 30
is transmitted by the contact portion 31b of the thread tension
releasing arm 31 to the thread tension releasing operation member
12. In addition, as seen from a condition (b) illustrated in FIG.
6B, the contact portion 12a of the thread tension releasing
operation member 12, which is adjacent to the first thread tension
disk 13b, presses the operating point 13a of the first thread
tension disk 13b toward the thread tension releasing direction of
the arrow X6; therefore, the first thread tension disk 13b
separates from the second thread tension disk 13c by an opening
angle E2 (shown in FIG. 6B), thereby allowing the needle thread
tension adjustment mechanism 9 to loosen the needle thread tension.
Thus, in the condition (b) of FIG. 4B, the user of the known sewing
machine may desirably position a workpiece fabric such as a fabric
to be embroidered, on the needle plate 2 while the needle thread
tension is not released.
[0041] Further according to the know sewing machine, the user
rotates the presser bar lifting lever 30 further upward by a
maximum rotation angle C1 shown in FIG. 4C as the condition (b) of
FIG. 4B shifts to a condition (c) illustrated in FIG. 4C. Then, the
presser bar holding member 20 is moved upward along with the
presser bar 5 in accordance with the lift amount of the cam surface
30a of the presser bar lifting lever 30 toward the upward direction
of the arrow Y1. As a result, the upper end of the presser bar 5 is
moved further upward by a distance C2 from the lower position to a
position shown in FIG. 4C. In the condition (c) of FIG. 4C, the
lift amount of the cam surface 30b does not vary from the condition
(b) of FIG. 4B; therefore, the needle thread tension adjustment
mechanism 9 is maintained in the inactive mode; therefore, the
needle thread tension remains loosened. In addition, the cam
surface 30a of the presser bar lifting lever 30 does not have a
flat surface; therefore, the presser bar holding member 20 may not
be maintained in the position shown in FIG. 4C and thereby moves
downward.
[0042] In other words, in the condition (c) of FIG. 4C illustrating
the known sewing machine, a contact position between the presser
bar holding member 20 and the presser bar lifting lever 30 is away
from the rotary shaft 1c by a distance LB. Further, a moment FW due
to the biasing force of the presser spring 22 acts in a direction
to rotate the presser bar lifting lever 30 downward about the
rotary shaft 1c. Thus, according to the known sewing machine, when
the user releases his/her hand from the presser bar lifting lever
30 in the condition (c) of FIG. 4C, the presser bar lifting lever
30 automatically returns to the condition (b) of FIG. 4B due to the
biasing force of the presser spring 22. In the case of sewing of a
folded portion of a workpiece fabric such as a denim fabric having
a thickness appropriately equal to the distance B2, the user of the
known sewing machine inserts the workpiece fabric under the presser
foot 6. At this time, for example, the presser bar lifting lever 30
is moved upward by the distance B2 only; therefore, the user of the
known sewing machine may not easily place the workpiece fabric
under the presser foot 6. Accordingly, the user of the known sewing
machine moves the presser bar 5 and the presser foot 6 upward
approximately by the distance C2 from the lower position of FIG. 4A
to the position of FIG. 4C so as to easily place the workpiece
fabric under the presser foot 6, thereby increasing the sewing
efficiency. Meanwhile, for example, the presser bar 5 and the
presser foot 6 are moved upward by the distance C2 from the lower
position to the position of FIG. 4C and are maintained thereat.
Then, the sewing needle 50 moves down toward the needle plate 2. At
this time, a needle clamp 8 may make contact with the presser foot
6; therefore, the presser foot 6 may be damaged. Accordingly, the
known sewing machine is configured as described above to
automatically return the presser bar 5 and the presser foot 6 from
the position of FIG. 4C to the first holding position of FIG. 4B,
thereby preventing the aforementioned damage of the presser foot 6
due to the contact with the needle clamp 8. Moreover, according to
the known sewing machine, when the presser bar lifting lever 30 is
maintained in the first holding position of FIG. 4B, the user may
not easily place the embroidery frame under the presser foot 6 and
the first thread tension disk 13b is separated from the second
thread tension disk 13c. Accordingly, the user of the known sewing
machine needs to move the presser bar lifting lever 30 downward so
as to appropriately operate the sewing machine in the embroidery
mode; however, the user of the sewing machine may forget to lift
down the presser foot lifting lever 30 before doing embroidery. As
described above, the presser bar lifting lever 30 is configured to
automatically return from the condition (c) of FIG. 4C to the
condition (b) of FIG. 4B, thereby preventing the user of the sewing
machine from forgetting to lift down the presser foot lifting lever
30 before doing embroidery.
[0043] Next, a mechanism of the presser bar lifting lever 3
according to the embodiment will be explained with reference to
FIGS. 7 to 9 as follows. FIG. 8 illustrates the presser bar lifting
lever 3 according to the embodiment. The presser bar lifting lever
3 includes the height adjustment cam portion 3H for adjusting the
position of the presser bar 5 in the vertical direction and the
position of the presser foot 6 in the vertical direction, and a
thread tension adjustment cam portion 3T for allowing the needle
thread tension adjustment mechanism 9 to adjust the needle thread
tension. The height adjustment cam portion 3H and the thread
tension adjustment cam portion 3T are formed at different portions
of the presser bar lifting lever 3 as illustrated in hatched areas
in FIG. 8. The height adjustment cam portion 3H and the thread
tension adjustment cam portion 3T are arranged at an opposite side
from the operation portion 3w manually operated by the user of the
sewing machine in the vertical direction. The presser bar lifting
lever 3 includes the switch lever operation arm 3f extending in the
longitudinal direction of the main body 1. As illustrated in FIG.
8, a cam profile of the height adjustment cam portion 3H includes a
neutral cam surface 3a for arranging the presser bar 5 in a lower
position (see FIG. 7A) when the sewing machine is operable in the
normal sewing mode, the first cam surface 3c for arranging the
presser bar 5 in the first holding position in which the presser
bar 5 is moved further upward from the lower position, and the
second cam surface 3d for arranging the presser bar 5 in the second
holding position in which the presser bar 5 is moved further upward
from the first holding position and for holding the presser bar 5
in the second holding position so as not to move downward
therefrom.
[0044] In addition, a cam profile of a cam surface 3b of the thread
tension adjustment cam portion 3T of the presser bar lifting lever
3 functions as follows: (a) When the presser bar 5 is in the lower
position, the cam profile of the cam surface 3b of the thread
tension adjustment cam portion 3T brings the needle thread tension
adjustment mechanism 9 into the active mode and allows the first
thread tension disk 13b to be closed relative to the second thread
tension disk 13c, in order for the sewing machine to be operable in
the normal sewing mode; (b) When the presser bar 5 is maintained in
the first holding position, the cam profile of the cam surface 3b
of the thread tension adjustment cam portion 3T brings the needle
thread tension adjustment mechanism 9 into the inactive mode to
thereby release the needle thread tension; and (c) When the presser
bar 5 is maintained in the second holding position, the cam profile
of the cam surface 3b of the thread tension adjustment cam portion
3T brings the needle thread tension adjustment mechanism 9 into the
active mode and allows the first tension disk 13b to be closed
relative to the second thread tension disk 13c, in order for the
sewing machine to be operable in the normal sewing mode.
[0045] FIG. 7A illustrates a condition (a) where the presser bar
lifting lever 3 is manually rotated down by the user of the sewing
machine around the rotary shaft 1c. In the condition (a) of FIG.
7A, in the condition where the presser foot 6 is attached to the
presser bar 5 (the sewing machine is in the normal sewing mode),
the presser bar 5 is biased by the biasing force of the presser
spring 22 toward a downward direction indicated by an arrow Y2 and
the presser foot 6 is pressed against the needle plate 2.
Accordingly, a clearance A4 is generated between the neutral cam
surface 3a of the height adjustment cam portion 3H of the presser
bar lifting lever 3 and the contact portion 20c of the presser bar
holding member 20 (refer to the condition (a) of FIG. 7A). At this
time, as seen from FIG. 9, a contact portion 23a of the thread
tension releasing arm 23 may make contact with the presser bar
lifting lever 3 and the thread tension releasing arm 23 is moved in
a thread tension releasing direction (indicated by an arrow X5 in
FIG. 9) in accordance with a lift amount of the cam surface 3b of
the thread tension adjustment cam portion 3T of the presser bar
lifting lever 3. That is, the lift amount of the cam surface 3b of
the thread tension adjustment cam portion 3T of the presser bar
lifting lever 3 is transmitted via the contact portion 23b of the
thread tension releasing arm 23 to the thread tension releasing
operation member 12. Accordingly, the clearance D1 is generated
between the operating point 13a of the first thread tension disk
13b and the contact portion 12a of the thread tension releasing
operation member 12 (refer to FIG. 6A). As a result, the first
thread tension disk 13b is closed relative to the second thread
tension disk 13c; thereby, the needle thread tension adjustment
mechanism 9 is in the active mode. Consequently, the sewing machine
may be operated in the normal sewing mode by the user under the
condition (a) of FIG. 7A (the sewing machine may be operated in the
normal sewing mode by the user in the same way as the known sewing
machine).
[0046] As the condition (a) of FIG. 7A shifts to a condition (b)
illustrated in FIG. 7B, the user of the sewing machine manually
rotates the presser bar lifting lever 3 upward about the rotary
shaft 1c by a rotation angle B1. Then, the contact portion 20c of
the presser bar holding member 20 moves toward an upward direction
(indicated by an arrow Y1 in FIG. 7A) in accordance with a lift
amount of the first cam surface 3c of the height adjustment cam
portion 3H of the presser bar lifting lever 3. In addition, the
upper end of the presser bar 5 is moved upward by a distance B2
from the lower position in FIG. 7A to the first holding position
shown in FIG. 7B and is maintained thereat. Here, as shown in FIG.
7B, the first cam surface 3c having a flat surface is in contact
with the contact portion 20c of the presser bar holding member 20.
At this time, the first cam surface 3c is positioned on a straight
line P passing through a central axis of the rotary shaft 1c so as
to be perpendicular to the central axis as illustrated in the
condition (b) of FIG. 7B. In addition, the first cam surface 3c
extends along a horizontal direction in FIG. 7B. Accordingly, a
downward force FM due to the biasing force of the presser spring 22
substantially acts along the straight line P. Consequently, in the
condition (b) of FIG. 7B, a moment to rotate the presser bar
lifting lever 3 downward about the rotary shaft 1c is not
substantially generated. Under such condition, the contact portion
23a makes contact with the presser bar lifting lever 3 and the
thread tension releasing arm 23 rotates in the thread tension
releasing direction of the arrow X5 in accordance with the lift
amount (a section 3e illustrated in FIG. 9) of the cam surface 3b
of the thread tension adjustment cam portion 3T of the presser bar
lifting lever 3. In addition, the lift amount of the cam surface 3b
of the thread tension adjustment cam portion 3T of the presser bar
lifting lever 3 is transmitted to the thread tension releasing
operation member 12 via the contact portion 23b that is in the
opposite direction from the contact portion 23a in the vertical
direction. Then, the thread tension releasing operation member 12
rotates about the rotary shaft 1a by a rotation angle E1 in the
thread tension releasing direction indicated by the arrow X5 in
FIG. 5 and by the arrow X5 in FIG. 13. Consequently, as seen from
FIGS. 6A and 6B, the contact portion 12a of the thread tension
releasing operation member 12 presses the operating point 13a of
the first thread tension disk 13b in the thread tension releasing
direction of the arrow X6; thereby, the first thread tension disk
13b separates from the second thread tension disk 13c and therefore
has the opening angle E2 relative to the second thread tension disk
13c. As a result, the needle thread tension adjustment mechanism 9
is allowed to loosen the needle thread tension. Thus, in the
condition (b) of FIG. 7B, the user of the sewing machine may
desirably position the workpiece fabric to be embroidered, on the
needle plate 2 (the presser bar lifting lever 3 in the condition
(b) of FIG. 7B functions in the same way as in the presser bar
lifting lever 30 in the condition (b) of FIG. 4B).
[0047] The sewing machine according to the embodiment differs from
the known sewing machine as follows. In a condition where the
holder 4 and the presser foot 6 are not attached to the presser bar
5, the user of the sewing machine manually rotates the presser bar
lifting lever 3 about the rotary shaft 1c further upward (by a
maximum rotation angle C1) as the condition (b) of FIG. 7B shifts
to a condition (c) illustrated in FIG. 7C. At this time, the
contact portion 20c of the presser bar holding member 20 and the
presser bar 5 move further upward (toward the upward direction of
the arrow Y1) in accordance with a lift amount of the second cam
surface 3d of the height adjustment cam portion 3H of the presser
bar lifting lever 3; thereafter, the second cam surface 3d having a
flat surface makes contact with the contact portion 20c of the
presser bar holding member 20. As illustrated in FIG. 7C, when the
second cam surface 3d is in contact with the contact portion 20c,
the second cam surface 3d is positioned on the straight line P
passing through the central axis of the rotary shaft 1c of the
presser bar lifting lever 3 so as to be perpendicular to the
central axis. In addition, the second cam surface 3d extends along
a horizontal direction in FIG. 7C. Accordingly, the downward force
FM due to the biasing force of the presser spring 22 substantially
acts along the straight line P. Consequently, the moment to rotate
the presser bar lifting lever 3 downward about the rotary shaft 1c
is not substantially generated. As a result, the presser bar 5 is
moved upward by a distance C2 from the lower position in FIG. 7A to
the second holding position in FIG. 7C and is thereafter maintained
thereat. In the condition (c) of FIG. 7C, the presser bar lifting
lever 3 is moved further upward from the condition (b) of FIG. 7B
and the cam surface 3b of the thread tension adjustment cam portion
3T is away from the section 3e in the same way as the presser bar
lifting lever 3 in the condition (a) of FIG. 7A. Accordingly, the
first thread tension disk 13b is closed relative to the second
thread tension disk 13c and the needle thread tension adjustment
mechanism 9 returns to the active mode. As a result, according to
the embodiment, the user of the sewing machine may do embroidery,
freehand embroidery, or the like by using the embroidery frame in
the condition (c) of FIG. 7C (the function of the presser bar
lifting lever 3 of the sewing machine in the condition (c) of FIG.
7C is different from the function of the presser bar lifting lever
30 of the known sewing machine in the condition (c) of FIG.
4C).
[0048] Next, a detecting function of the switch for the position of
the presser bar lifting lever 3 will be explained as follows with
reference to FIGS. 10A to 10C. The position of the presser bar
lifting lever 3 in each of FIGS. 10A to 10C corresponds to the
position of the presser bar lifting lever 3 in each of the FIG. 7A
to 7C. The switch lever 15 including the operation bore 15a is
attached to the main body 1 so as to rotate about the rotary shaft
16a that is arranged at a different position from the rotary shaft
1c. The operation bore 15a is formed so as to have the elongated
shape. The switch lever operation arm 3f integrally formed with the
presser bar lifting lever 3 is fitted to the operation bore 15a.
Accordingly, in the condition (a) of FIG. 10A where the presser bar
lifting lever 3 is moved downward to the lower position, the switch
lever 15 and the operation bore 15a are moved downward. Further,
the switch lever 15 is rotated by the biasing force of the switch
lever spring 17 about the rotary shaft 16a in the first direction
indicated by an arrow R2 (the first direction of the arrow R2
corresponds to a counterclockwise direction in FIG. 10A). At this
time, the intermediate contact point 18a of the leaf switch 18 is
pressed by the first operation arm 15b of the switch lever 15
toward the first direction of the arrow R2, thereby electrically
connecting the switch lever 15 to a first contact point 18b of the
leaf switch 18. As a result, the switch outputs an ON signal 1
(first ON signal) to a control unit. For example, in a case where a
thick workpiece fabric is being sewed by the sewing machine, the
clearance A4 between the neutral cam surface 3a of the height
adjustment cam portion 3H of the presser bar lifting lever 3 and
the contact portion 20c of the presser bar holding member 20
increases; therefore, the presser bar lifting lever 3 may easily
move upward. Thus, when the position of the presser bar lifting
lever 3 in the vertical direction easily changes, the presser bar
lifting lever 3 is moved upward by a returning force of the leaf
switch 18 and the leaf switch 18 may be electrically disconnected
from the switch lever 15; therefore, the switch lever spring 17
biasing the switch lever 15 toward the first direction of the arrow
R2 is provided in order to prevent the disconnection between the
leaf switch 18 and the switch lever 15. In addition, the switch
lever spring 17 may be formed by any member as long as serving as
an elastic body.
[0049] In the condition (b) illustrated in FIG. 10B where the
presser bar lifting lever 3 is maintained in the first holding
position, the presser bar lifting lever 3 is rotated upward (in a
second direction indicated by an arrow R1 in FIG. 10B) about the
rotary shaft 1c by a rotation angle B1; therefore, the switch lever
15 including the operation bore 15a is moved upward about the
rotary shaft 16a toward the second direction of the arrow R1 by the
switch lever operation arm 3f integrally formed with the presser
bar lifting lever 3. Accordingly, the switch lever 15 rotates
against the biasing force of the switch lever spring 17 toward the
second direction of the arrow R1. At this time, the first operation
arm 15b and the second operation arm 15c of the switch lever 15 are
not in contact with the intermediate contact point 18a while not
pressing the intermediate contact point 18a. Accordingly, the leaf
switch 18 is not electrically connected to the switch lever 15;
therefore, the switch outputs an OFF signal to the control
unit.
[0050] Moreover, in the condition (c) illustrated in FIG. 10C where
the presser bar lifting lever 3 is maintained in the second holding
position, the presser bar lifting lever 3 is rotated about the
rotary shaft 1c by a rotation angle C1 from the condition (b) of
FIG. 10B. Accordingly, the operation bore 15a is moved further
upward by the switch lever operation arm 3f compared to the
condition (b) of FIG. 10B. The operation bore 15a has the elongated
shape; thereby, the switch lever operation arm 3f moves along the
operation bore 15a. Accordingly, the switch lever 15 rotates
against the biasing force of the switch lever spring 17 toward the
second direction of the arrow R1. At this time, the intermediate
point 18a of the leaf switch 18 is pressed by the second operation
arm 15c of the switch lever 15; therefore, the leaf switch 18 is
electrically connected to the switch lever 15. As a result, the
switch outputs an ON signal 2 (second ON signal) to the control
unit.
[0051] As described above, the switch outputs the ON signal 1, the
OFF signal, and the ON signal 2 for the lower position, the first
holding position, and the second holding position of the presser
bar lifting lever 3, respectively. The ON signal 1, the OFF signal,
and the ON signal 2 are input to a microcomputer of the main body 1
of the sewing machine and are thereafter processed by the
microcomputer. Thus, the sewing machine operates in modes shown in
Table 1.
TABLE-US-00001 TABLE 1 Position of the presser bar lifting lever 3
in the Output vertical of the Operation mode of direction switch
the sewing machine Lower position ON The normal sewing mode is
executable. signal 1 The sewing machine is operable. (The user of
the sewing machine may select a sewing pattern related only to the
normal sewing mode.) First holding OFF Operations in sewing and
embroidery position signal modes are not executable. The sewing
machine is not operable. (The user of the sewing machine is warned
that the sewing machine is not operable.) Second holding ON Only
the embroidery mode is executable. position signal 2 The sewing
machine is operable. (The user of the sewing machine may select a
sewing pattern related only to the embroidery mode, the freehand
embroidery mode, or the like.)
[0052] FIG. 11 is a chart showing a relation between a rotation
angle of the presser bar lifting lever 3 and a vertical movement
distance of the presser bar 5 and the presser foot 6 and a relation
between the rotation angle of the presser bar lifting lever 3 and
an opening angle of the first thread tension disk 13b relative to
the second thread tension disk 13c. A characteristic curved line B1
indicates the vertical movement distance of the presser bar 5 and
the presser foot 6 of the sewing machine according to the
embodiment. A characteristic curved line B2 indicates the vertical
movement distance of the presser bar 5 and the presser foot 6 of
the known sewing machine. A characteristic line C1 indicates the
opening angle of the first thread tension disk 13b relative to the
second thread tension disk 13c according to the sewing machine of
the embodiment. A characteristic line C2 indicates the opening
angle of the first thread tension disk 13b relative to the second
thread tension disk 13c according to the known sewing machine.
[0053] According to the known sewing machine, as shown by the
characteristic curved line B2 in FIG. 11, the first holding
position to which the presser bar 5 and the presser foot 6 are
moved upward from the lower position is indicated by a point F2.
Further, the position located further upward than the first holding
position (the position corresponding to the second holding position
to which the presser bar 5 and the presser foot 6 of the sewing
machine of the embodiment is moved further upward from the first
holding position) is indicated by a point F3. Meanwhile, according
to the sewing machine of the embodiment, as shown by the
characteristic curved line B1 in FIG. 11, the first holding
position to which the presser bar 5 and the presser foot 6 are
moved upward from the lower position is indicated by a point F1.
Further, the position to which the presser bar 5 and the presser
foot 6 are moved further upward from the first holding position is
indicated by the point F3. The presser bar 5 and the presser foot 6
are maintained in both the first holding position of the point F1
and the second holding position of the point F3 so as not to move
downward due to gravity. In addition, according to the known sewing
machine, as shown by the characteristic line C2, the first thread
tension disk 13b separates from the second thread tension disk 13c
so as to have therebetween the opening angle E2 until the presser
bar 5 and the presser foot 6 are moved upward from the lower
position to the first holding position of the point F2 and are
maintained thereat. After the presser bar 5 and the presser foot 6
are moved further upward than the first holding position F2, the
first thread tension disk 13b remains separated from the second
thread tension disk 13c while keeping the opening angle E2 to the
second thread tension disk 13c. Meanwhile, according to the sewing
machine of the embodiment, as indicated by the characteristic line
C1, the first thread tension disk 13b separated from the second
thread tension disk 13c is closing toward the second thread tension
disk 13c for a period of time tc while the position of the presser
bar 5 and the presser foot 6 shifts from the first holding position
of the point F1 to the second holding position of the point F3.
Afterward, when the presser bar 5 and the presser foot 6 reach the
second holding position of the point F3, the opening angle E2
between the first thread tension disk 13b and the second thread
tension disk 13c reaches zero. At this time, the first thread
tension disk 13b is completely closed relative to the second thread
tension disk 13c. In addition, according to the known sewing
machine and the sewing machine of the embodiment, a condition where
the vertical movement distance is zero is applied to the normal
sewing mode. Moreover, according to the sewing machine of the
embodiment, a condition where the presser bar 5 and the presser
foot 6 are moved further upward from the first holding position of
the point F1 to the second holding position of the point F3 is
applied to the embroidery mode. Even when the user of the sewing
machine does embroidery by desirably positioning the embroidery
frame on the needle plate 2 under the aforementioned condition
where the presser bar 5 and the presser foot 6 are maintained in
the second holding position, the embroidery frame is prevented from
making contact with the presser bar 5. In addition, even when the
user of the sewing machine does freehand embroidery by desirably
and manually moving the embroidery frame on the needle plate 2, the
embroidery frame is prevented from making contact with the presser
bar 5.
[0054] As illustrated in FIGS. 12A and 12B, the stopper 7
(embroidery restriction member) having an extended shaft shape is
arranged at the lower surface 1u of the main body 1 so as to
protrude downward from the lower surface 1u as described above. A
height from the needle plate 2 to the lower end 7a of the stopper 7
is adjustable; however, the stopper 7 is designed so that the lower
end 7 is positioned higher than the position of the lower end 5d of
the presser bar 5 in the vertical direction. Further, the position
of the lower end 7a of the stopper 7 in the vertical direction is
adjusted so as to make contact with the upper surface 4a of the
holder 4 for the presser foot 6 before the presser bar lifting
lever 3 is maintained in the second holding position (before the
presser bar lifting lever 3 shifts to the condition (c) in FIG.
7C). In other words, when the user of the sewing machine intends to
operate the sewing machine in the embroidery mode under a condition
(a) illustrated in FIG. 12A where the holder 4 and the presser foot
6 are attached to the presser bar 5, the user of the sewing machine
rotates the presser bar lifting lever 3 upward so as to move the
presser bar 5 in an upward direction (indicated by an arrow Y1) and
to hold the presser bar 5 in the second holding position. At this
time, the upper surface 4a of the holder 4 for the presser foot 6
makes contact with the lower end 7a of the stopper 7. As a result,
the user of the sewing machine is surely restricted from allowing
the presser bar lifting lever 3 and the presser bar 5 to be
maintained in the second holding position under the condition (a)
of FIG. 12A. That is, the sewing machine is surely prevented from
operating in the embroidery mode when the holder 4 and the presser
foot 6 are attached to the presser bar 5. In addition, the presser
foot 6 may be prevented from making contact with the embroidery
frame and the needle clamp 8 may be prevented from making contact
with the presser foot 6. According to the sewing machine of the
embodiment, the presser foot 6 may be configured to make contact
with the lower end 7a of the stopper 7 instead of the holder 4.
[0055] As illustrated in FIG. 13, the thread tension releasing
operation member 12 rotates about the rotary shaft 1a. When the
user of the sewing machine manually rotates the presser bar lifting
lever 3 upward, the contact portion 23b of the thread tension
releasing arm 23 is moved in the thread tension releasing direction
(indicated by an arrow X5) by the thread tension adjustment cam
portion 3T of the presser bar lifting lever 3 (refer to FIG. 9).
Then, the thread tension releasing operation member 12 rotates
about the rotary shaft 1a in thread tension releasing directions
(indicated by arrows X5 and X6); therefore, the contact portion 12a
moves the operating point 13a of the first thread tension disk 13b
in the thread tension releasing direction of the arrow X6. As a
result, the first thread tension disk 13b separates from the second
thread tension disk 13c to release the needle thread tension
accordingly. As described above, the user of the sewing machine
manually rotates the presser bar lifting lever 3 upward to thereby
release the needle thread tension. Further, as illustrated in FIG.
13, a shaft 12b serving as a protruding portion is arranged at the
thread tension releasing operation member 12. Further, the rod 11
formed to extend from the automatic thread tension disk
opening/closing mechanism 10 is attached to the thread tension
releasing operation member 12. An elongated bore 11a extending in a
longitudinal direction of the rod 11 is formed therein in the
vicinity of the thread tension releasing operation member 12. The
shaft 12b of the thread tension releasing operation member 12 is
fitted to the elongated bore 11a so as to move therealong in the
longitudinal direction. A space of the elongated bore 11a, which is
in the opposite direction from the contact portion 23b of the
thread tension releasing arm 23 in the longitudinal direction of
the rod 11, i.e. a space of the elongated bore 11a, which is
positioned in the vicinity of an extending portion of the rod 11,
serves as a free space 11x. The shaft 12b of the thread tension
releasing operation member 12 is movable in the free space 11x
along the longitudinal direction of the rod 11 and is normally
positioned close to a wall portion 11y arranged at one of sides of
the rod 11 in the longitudinal direction (positioned in the
vicinity of the thread tension releasing operation member 12).
[0056] For example, the automatic thread tension disk
opening/closing mechanism 10 operates so as to separate the first
thread tension disk 13b from the second thread tension disk 13c
under a condition where the sewing machine is in the embroidery
mode or the like. Then, the rod 11 moves in the thread tension
releasing direction of the arrow X5 and the shaft 12b of the thread
tension releasing operation member 12 is pulled by the wall portion
11y in the thread tension releasing direction of the arrow X5;
therefore, the thread tension releasing operation member 12 rotates
about the rotary shaft 1a toward the thread tension releasing
directions of the arrow X5 and the arrow X6. At this time, the
contact portion 12a of the thread tension releasing operation
member 12 moves the operating point 13a of the first thread tension
disk 13b in the thread tension releasing direction of the arrow X6
and the first thread tension disk 13b separates from the second
thread tension disk 13c. As a result, the needle thread tension is
released. Thus, the motor 10c of the automatic thread tension disk
opening/closing mechanism 10 is driven to pull the rod 11 in the
thread tension releasing direction of the arrow X5, thereby
automatically releasing the needle thread tension. In such case,
even when the free space 11x is arranged in the elongated bore 11a,
the thread tension releasing operation member 12 appropriately
rotates about the rotary shaft la toward the thread tension
releasing directions of the arrows X5 and X6 and the needle thread
tension may be automatically released by the automatic thread
tension disk opening/closing mechanism 10.
[0057] Moreover, the manual operation of the presser bar lifting
lever 3 by the user of the sewing machine in a condition where the
first thread tension disk 13b is not separated from the second
thread tension disk 13c by the automatic thread tension disk
opening/closing mechanism 10, i.e. in a condition where the rod 11
is not pulled in the thread tension releasing direction of the
arrow X5 by the automatic thread tension disk opening/closing
mechanism 10, will be explained as follows. In the aforementioned
manual operation of the presser bar lifting lever 3 by the user of
the sewing machine, the contact portion 23b of the thread tension
releasing arm 23 is moved in the thread tension releasing direction
of the arrow X5 by the thread tension adjustment cam portion 3T of
the presser bar lifting lever 3 as illustrated in FIG. 13. Then,
the contact portion 12a of the thread tension releasing operation
member 12 rotates about the rotary shaft 1a in the thread tension
releasing direction of the arrow X6 and thereby moves the operating
point 13a of the thread tension disk 13 in the thread tension
releasing direction of the arrow X6. Accordingly, the first thread
tension disk 13b separates from the second thread tension disk 13c,
therefore releasing the needle thread tension. At this time, the
shaft 12b of the thread tension releasing operation member 12 moves
from the wall portion 11y to the free space 11x in the elongated
bore 11a along the longitudinal direction. Thus, even when the
shaft 12b of the thread tension releasing operation member 12 moves
from the wall portion 11y to the free space 11x in the elongated
bore 11a along the thread tension releasing direction of the arrow
X5, the free space 11x is arranged in the elongated bore 11a and
therefore the shaft 12b vibrates in the free space 11x.
Consequently, the shaft 12b does not push the rod 11 toward the
opposite direction from the thread tension releasing direction of
the arrow X5; therefore, the rod 11 is not moved due to the
vibrations of the shaft 12b in the free space 11x. As a result, the
rotation of the thread tension releasing operation member 12 due to
the manual operation of the presser bar lifting lever 3 is
refrained from affecting the automatic thread tension disk
opening/closing mechanism 10.
[0058] As described above, according to the sewing machine of the
embodiment, when operating the sewing machine in the embroidery
mode, the freehand embroidery mode, or the like by means of the
embroidery frame, the user of the sewing machine manually rotates
the presser bar lifting lever 3 upward to allow the presser bar 5
to be maintained in the second holding position. Accordingly, an
upper surface of the embroidery frame does not make contact with
the lower end 5d of the presser bar 5 in the vertical direction. In
addition, when the presser bar 5 is maintained in the second
holding position, the needle thread tension adjustment mechanism 9
is in the active mode and the first thread tension disk 13b is
closed relative to the second thread tension disk 13c, therefore
allowing the user of the sewing machine to appropriately do
freehand embroidery by using the needle thread.
[0059] The aforementioned effect according to the embodiment is
realized by a mechanical mechanism without addition of an actuator
and may be obtained at low cost. According to the known sewing
machine, for example, in a case where the presser bar lifting lever
30 is not moved downward by the user of the sewing machine before
doing freehand embroidery, the needle thread tension adjustment
mechanism 9 does not shift to the active mode and the needle thread
tension remains loosened. Moreover, according to the known sewing
machine, the lower end 5d of the presser bar 5 is positioned in
such a manner to contact the upper surface of the embroidery frame
in the vertical direction. Accordingly, when doing embroidery,
freehand embroidery, or the like, the user of the sewing machine
needs to be careful so that the upper surface of the embroidery
frame does not make contact with the lower end 5d of the presser
bar 5 in the vertical direction.
[0060] According to the configuration of the sewing machine of the
embodiment as described above, the switch may detect three
rotational positions of the presser bar lifting lever 3 such as the
lower position, the first holding position, and the second holding
position. In a condition where the presser bar lifting lever 3 is
moved down by the user of the sewing machine to the lower position,
the sewing machine is operable in the normal sewing mode and may
select the sewing pattern related only to the normal sewing mode.
Further, in a condition where the presser bar lifting lever 3 is
moved by the user of the sewing machine to the second holding
position and is maintained thereat, the swing machine is operable
in the embroidery mode and the user may select the sewing pattern
related only to the embroidery mode, the freehand embroidery mode,
or the like. Accordingly, usability and safety of the user of the
sewing machine may increase. Furthermore, in a condition where the
presser bar lifting lever 3 is moved by the user of the sewing
machine to the first holding position and is maintained thereat,
the sewing machine is not operable in the same way as the known
sewing machine; thereby, the safety of the user of the sewing
machine may be maintained. Such effect may be realized by the
simply configured switch and the mechanical mechanism; therefore,
the inexpensive sewing machine may be obtained. In addition,
according to the known sewing machine, a switch is applied to
thereby detect two rotational positions of the presser bar lifting
lever 30.
[0061] Moreover, according to the aforementioned configuration of
the sewing machine of the embodiment, for example, even when the
user of the sewing machine accidentally tries to do embroidery,
freehand embroidery, or the like under a condition where the
presser foot 6 is attached to the lower end 5d of the presser bar
5, the presser bar lifting lever 3 may not be moved upward to the
second holding position and may not be maintained thereat;
therefore, the user of the sewing machine may not shift the sewing
machine from the normal sewing mode to the embroidery mode. Thus,
the user of the sewing machine may not operate the sewing machine
in the embroidery mode, the freehand embroidery mode, or the like
in a condition where the presser foot 6 is accidentally attached to
the lower end 5d of the presser bar 5 by the user of the sewing
machine.
[0062] The configuration of the sewing machine according to the
disclosure is not limited to the embodiment described above and
illustrated in the attached drawings, and may be modified according
to need as long as not deviating from the purpose of the
disclosure.
[0063] As described above, according to the aforementioned
embodiment, the sewing machine includes the main body 1, the
presser bar 5 attached to the main body 1 so as to move along the
vertical direction of the sewing machine and detachably holding the
presser foot 6 at the lower end 5d, the needle thread tension
adjustment mechanism 9 selectively brought into the inactive and
active modes, the needle thread tension adjustment mechanism 9
releasing the needle thread tension in the inactive mode and
maintaining the needle thread tension in the active mode, and the
presser bar lifting lever 3 manually rotated about the rotary shaft
1c along the vertical direction by the user of the sewing machine
and provided so as to adjust the position of the presser bar 5 in
the vertical direction in accordance with the manual rotation, the
presser bar lifting lever 3 including the height adjustment cam
portion 3H adjusting the position of the presser bar 5 in the
vertical direction and the thread tension adjustment cam portion 3T
allowing the needle thread tension adjustment mechanism 9 to adjust
the needle thread tension. The height adjustment cam portion 3H of
the presser bar lifting lever 3 includes the cam profile arranging
the presser bar 5 in the lower position in which the sewing machine
is operable in the normal sewing mode. The cam profile of the
height adjustment cam portion 3H allows the presser bar 5 to be
maintained in the first holding position to which the presser bar 5
is moved further upward from the lower position in the vertical
direction. The cam profile of the height adjustment cam portion 3H
allows the presser bar 5 to be maintained in the second holding
position to which the presser bar 5 is moved further upward from
the first holding position in the vertical direction. The thread
tension adjustment cam portion 3T of the presser bar lifting lever
3 includes the cam profile bringing the needle thread tension
adjustment mechanism 9 into the active mode when the presser bar 5
is in the lower position. The cam profile of the thread tension
adjustment cam portion 3T brings the needle thread tension
adjustment mechanism 9 into the inactive mode when the presser bar
5 is in the first holding position. The cam profile of the thread
tension adjustment cam portion 3T brings the needle thread tension
adjustment mechanism 9 into the active mode when the presser bar 5
is in the second holding position.
[0064] According to the aforementioned embodiment, the presser bar
5 includes the presser bar holding member 20 supported by the
presser bar 5. The cam profile of the height adjustment cam portion
3H of the presser bar lifting lever 3 includes the first cam
surface 3c being in contact with the presser bar holding member 20
at the upper side of the rotary shaft 1c and positioned on the
straight line P when the presser bar 5 is in the first holding
position, the straight line P passing through the central axis of
the rotary shaft 1c so as to be perpendicular to the central axis,
and the second cam surface 3d being in contact with the presser bar
holding member 20 at the upper side of the rotary shaft 1c and
positioned on the straight line P when the presser bar 5 is in the
second holding position.
[0065] Accordingly, even when the user of the sewing machine does
embroidery, freehand embroidery, or the like under a condition
where the presser bar lifting lever 3 is maintained in the second
holding position, the embroidery frame is prevented from making
contact with the presser bar 5; therefore, the user of the sewing
machine may appropriately operate the sewing machine in the
embroidery or freehand embroidery mode.
[0066] In other words, when the user of the sewing machine does
embroidery, freehand embroidery, or the like by using the
embroidery frame, the presser bar 5 may be maintained in the second
holding position so as not to move downward in order to prevent the
embroidery frame from making contact with the lower end 5d of the
presser bar 5. In addition, when the presser bar 5 is maintained in
the second holding position, the needle thread tension adjustment
mechanism 9 maintains the needle thread tension; therefore, the
needle thread tension for the embroidery or freehand embroidery may
be realized by an inexpensive mechanism. In particular, when the
user of the sewing machine does embroidery, freehand embroidery, or
the like by using the embroidery frame, the presser bar 5 is
maintained at the upper side of the upper surface of the embroidery
frame and the needle thread tension adjustment mechanism 9 adjusts
the needle thread tension suitably for the embroidery or freehand
embroidery. As a result, the user of the sewing machine may
appropriately or desirably do embroidery, freehand embroidery, or
the like while not being affected by the contact between the
embroidery frame and the presser bar 5.
[0067] According to the aforementioned embodiment, the first cam
surface 3c of the cam profile of the height adjustment cam portion
3H extends along the horizontal direction of the sewing machine
when the presser bar 5 is in the first holding position. The second
cam surface 3d of the cam profile of the height adjustment cam
portion 3H extends along the horizontal direction of the sewing
machine.
[0068] Accordingly, the first cam surface 3c and the second cam
surface 3d of the presser bar lifting lever 3 may form the cam
profiles for holding the presser bar 5 and the presser bar holding
member 20 and preventing the presser bar 5 and the presser bar
holding member from moving downward. In such case, the presser bar
5 is moved to the first holding position and is maintained thereat.
As a result, under a condition where the presser bar 5 is
maintained in the first holding position, the needle thread tension
adjustment mechanism 9 is brought into the inactive mode and the
first thread tension disk 13b is separated from the second thread
tension disk 13c; therefore, the needle thread tension is loosened.
Meanwhile, in a condition where the presser bar 5 is maintained in
the second holding position, the needle thread tension adjustment
mechanism 9 is brought into the active mode and the first thread
tension disk 13b is closed relative to the second thread tension
disk 13c; therefore, the needle thread tension is maintained.
According to the aforementioned embodiment, the sewing machine
further includes the switch detecting the lower position, the first
holding position, and the second holding position of the presser
bar 5.
[0069] According to the aforementioned embodiment, the sewing
machine further includes the switch lever 15 rotating along with
the rotation of the presser bar lifting lever 3. The switch outputs
the ON signal 1 when detecting that the switch lever 15 is rotated
in the first direction R2. The switch outputs the OFF signal when
detecting that the switch lever 15 is rotated to the intermediate
position. The switch outputs the ON signal 2 when detecting that
the switch lever 15 is rotated in the second direction R1. The
sewing machine is operable in the normal sewing mode when the lower
position of the switch lever 15 is determined on the basis of the
ON signal 1 outputted from the switch. The sewing machine is not
operable in the normal sewing mode when the first holding position
of the switch lever 15 is determined on the basis of the OFF signal
outputted from the switch. The sewing machine is operable in the
normal sewing mode when the second holding position of the switch
lever 15 is determined on the basis of the ON signal 2 outputted
from the switch.
[0070] Thus, information required for automatically changing a
sewing pattern program along with the manual operation of the
presser bar lifting lever 3 by the user and information required
for safely activating the sewing machine may be provided by the
inexpensive and simply configured switch detecting the lower
position, the first holding position, and the second holding
position of the presser bar 5.
[0071] According to the aforementioned embodiment, the sewing
machine further includes the stopper 7 attached to the main body 1.
The stopper 7 makes contact with either one of the presser foot 6
and the holder 4 for attaching the presser foot 6 to the presser
bar 5, and restricts the presser bar 5 from shifting to the second
holding position in a state where the presser foot 6 is attached to
the presser bar 5.
[0072] Thus, the stopper 7 prevents the user of the sewing machine
from operating the sewing machine in the embroidery mode, the
freehand embroidery mode, or the like in a condition where the
presser foot 6 is accidentally attached to the lower end 5d of the
presser bar 5 by the user. In addition, the stopper 7 prevents the
presser foot 6 (or the holder 4) from making contact with the
needle clamp 8 under a condition where the presser bar lifting
lever 3 is maintained in the second holding position; therefore,
the damage of the embroidery frame and the presser foot 6 due to
the contact therebetween is prevented. As a result, the safety for
the user of the sewing machine may increase.
[0073] According to the aforementioned embodiment, the sewing
machine further includes the thread tension releasing operation
member 12 selectively bringing the needle thread tension adjustment
mechanism 9 into the inactive and active modes, the rod 11 engaged
with the thread tension releasing operation member 12, the motor
10c electrically operating the thread tension releasing operation
member 12 and the rod 11 to bring the needle thread tension
adjustment mechanism 9 into the inactive mode, and the thread
tension releasing arm 23 operating the thread tension releasing
operation member 12 in accordance with the manual rotation of the
presser bar lifting lever 3 by the user of the sewing machine to
bring the needle thread tension adjustment mechanism 9 into the
inactive mode. The thread tension releasing operation member 12
includes the shaft 12b and the rod 11 includes the elongated bore
11a having the free space 11x to which the shaft 12b of the thread
tension releasing operation member 12 is fitted. The elongated bore
11a is larger in size than the shaft 12b. When the motor 10c is
driven in the direction to move the rod 11 in the thread tension
releasing direction of the arrow X5, the thread tension releasing
operation member 12 is moved via the shaft 12b by the rod 11 to
bring the needle thread tension adjustment mechanism 9 into the
inactive mode.
[0074] In particular, when the motor 10c is rotatably driven in one
direction to move the rod 11 in the thread tension releasing
direction of the arrow X5, the thread tension releasing operation
member 12 is moved via the shaft 12b by the rod 11 to bring the
needle thread tension adjustment mechanism 9 into the inactive
mode. Further, when the motor 10c is rotatably driven in the other
direction to move the rod 11 in the opposite direction from the
thread tension releasing direction of the arrow X5, the elongated
bore 11a of the rod 11 is moved relative to the shaft 12b via the
free space 11x in the opposite direction to prevent the movement of
the rod 11 from being transmitted to the thread tension releasing
operation member 12.
[0075] According to the aforementioned embodiment, when the presser
bar lifting lever 3 is manually rotated by the user of the sewing
machine and the thread tension releasing operation member 12 is
moved by the thread tension adjustment cam portion 3T in the thread
tension releasing direction of the arrow X5 to bring the needle
thread tension adjustment mechanism 9 into the inactive mode, the
shaft 12b moves in the elongated bore 11a therealong and the free
space 11x of the elongated bore 11a prevents the movement of the
thread tension releasing operation member 12 from being transmitted
to the rod 11.
[0076] The principles, preferred embodiment and mode of operation
of the present invention have been described in the foregoing
specification. However, the invention which is intended to be
protected is not to be construed as limited to the particular
embodiments disclosed. Further, the embodiments described herein
are to be regarded as illustrative rather than restrictive.
Variations and changes may be made by others, and equivalents
employed, without departing from the spirit of the present
invention. Accordingly, it is expressly intended that all such
variations, changes and equivalents which fall within the spirit
and scope of the present invention as defined in the claims, be
embraced thereby.
* * * * *