U.S. patent application number 13/236087 was filed with the patent office on 2012-04-19 for embroidery frame.
This patent application is currently assigned to BROTHER KOGYO KABUSHIKI KAISHA. Invention is credited to Hiroaki FUKAO.
Application Number | 20120090519 13/236087 |
Document ID | / |
Family ID | 45932962 |
Filed Date | 2012-04-19 |
United States Patent
Application |
20120090519 |
Kind Code |
A1 |
FUKAO; Hiroaki |
April 19, 2012 |
EMBROIDERY FRAME
Abstract
An embroidery frame includes an outer frame formed into a
substantially annular shape and having a discontinuity formed by
partially breaking its annularity so that the outer frame has two
ends located opposite each other with the discontinuity being
interposed, an inner frame configured to be fitted with an inner
periphery of the outer frame, a clamping mechanism clamping the
outer frame against the inner frame and including paired
screw-supporting members mounted on the outer frame ends and an
adjusting screw mounted on the screw-supporting members so as to
adjust a gap between the screw mounting members, and an operating
knob supported on an operating end of the screw so as to be
switchable between a first position where the knob extends parallel
to an axial direction of the screw and a second position where the
knob extends in a direction substantially perpendicular to the
axial direction.
Inventors: |
FUKAO; Hiroaki;
(Kasugai-shi, JP) |
Assignee: |
BROTHER KOGYO KABUSHIKI
KAISHA
Nagoya-shi
JP
|
Family ID: |
45932962 |
Appl. No.: |
13/236087 |
Filed: |
September 19, 2011 |
Current U.S.
Class: |
112/103 |
Current CPC
Class: |
D05C 9/04 20130101 |
Class at
Publication: |
112/103 |
International
Class: |
D05C 9/04 20060101
D05C009/04 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 14, 2010 |
JP |
2010-231505 |
Claims
1. An embroidery frame which holds a workpiece cloth, comprising:
an outer frame formed into a substantially annular shape and having
a discontinuity formed by partially breaking the annularity of the
outer frame so that the outer frame has two ends located opposite
each other with the discontinuity being interposed therebetween; an
inner frame configured to be fitted with an inner periphery of the
outer frame so that the workpiece cloth is held between the outer
and inner frames; a clamping mechanism which clamps the outer frame
against the inner frame and includes a pair of screw-supporting
members provided on the ends of the outer frame respectively and an
adjusting screw which is mounted on the screw-supporting members so
as to be capable of adjusting a gap between the screw mounting
members; and an operating knob which is supported on an operating
end of the adjusting screw so as to be switchable between a first
position where the operating knob extends substantially in parallel
to an axial direction of the adjusting screw and a second position
where the operating knob extends in a direction substantially
perpendicular to the axial direction of the adjusting screw.
2. The embroidery frame according to claim 1, wherein the operating
knob has a lengthwise middle portion which is rotatably mounted on
a shaft member so as to be pivotable relative to the adjusting
screw, and the adjusting screw and the operating knob are located
so as to form a general T-shape when the operating knob assumes the
second position.
3. The embroidery frame according to claim 1, further comprising a
retaining member which retains the operating knob in each of the
first and second positions.
4. The embroidery frame according to claim 2, further comprising a
retaining member which retains the operating knob in each of the
first and second positions.
5. The embroidery frame according to claim 2, wherein: the
operating knob has a cutout groove which is formed in a part
thereof so as to extend in the lengthwise direction; the operating
end of the adjusting screw is provided with a generally flat
plate-shaped portion which is inserted into the cutout groove; the
shaft member is disposed so as to extend through the flat
plate-shaped portion; and the flat plate-shaped portion and the
cutout groove are caused to pivot relative to each other with
switch in the position of the operating knob.
6. The embroidery frame according to claim 4, wherein: the
operating knob has a cutout groove which is formed in a part
thereof so as to extend in the lengthwise direction; the operating
end of the adjusting screw is provided with a generally flat
plate-shaped portion which is inserted into the cutout groove; the
shaft member is disposed so as to extend through the flat
plate-shaped portion; and the flat plate-shaped portion and the
cutout groove are caused to pivot relative to each other with
change in the position of the operating knob.
7. The embroidery frame according to claim 1, wherein the operating
knob has two lengthwise ends each of which is formed into a convex
semispherical shape.
8. An embroidery frame which holds a workpiece cloth, comprising:
an outer frame formed into a substantially annular shape and having
a discontinuity formed by partially breaking the annularity of the
outer frame so that the outer frame has two ends located opposite
each other with the discontinuity being interposed therebetween; an
inner frame configured to be fitted with an inner periphery of the
outer frame so that the workpiece cloth is held between the outer
and inner frames; a clamping mechanism which clamps the outer frame
against the inner frame and includes a pair of screw-supporting
members provided on the ends of the outer frame respectively and an
adjusting screw which is mounted on the screw-supporting members so
as to be capable of adjusting a gap between the screw mounting
members; an operating shaft which rotates the adjusting screw and
is provided so as to be swingable between a first location where
central axes of the operating shaft and the adjusting screw extend
in an identical direction or a different direction and a second
location where the operating shaft is inclined in a direction such
that a gap between the outer frame and the operating shaft is
increased; a coupling mechanism which couples the operating shaft
with the adjusting screw to transmit a rotational torque of the
operating shaft; and an operating knob which is supported on an
operating end of the operating shaft so as to be switchable between
a first position where the operating knob extends substantially in
parallel to an axial direction of the operating shaft and a second
position where the operating knob extends in a direction
substantially perpendicular to the axial direction of the operating
shaft.
9. The embroidery frame according to claim 8, wherein the operating
knob has a lengthwise middle portion which is rotatably mounted on
a shaft member so as to be pivotable relative to the operating
shaft, and the operating shaft and the operating knob are located
so as to form a general T-shape when the operating knob assumes the
second position.
10. The embroidery frame according to claim 8, further comprising a
retaining member which retains the operating knob in each of the
first and second positions.
11. The embroidery frame according to claim 9, further comprising a
retaining member which retains the operating knob in each of the
first and second positions.
12. The embroidery frame according to claim 9, wherein: the
operating knob has a cutout groove which is formed in a part
thereof so as to extend in the lengthwise direction; the operating
end of the operating shaft is provided with a generally flat
plate-shaped portion which is inserted into the cutout groove; the
shaft member is disposed so as to extend through the flat
plate-shaped portion; and the flat plate-shaped portion and the
cutout groove are caused to pivot relative to each other with
switch in the position of the operating knob.
13. The embroidery frame according to claim 11, wherein: the
operating knob has a cutout groove which is formed in a part
thereof so as to extend in the lengthwise direction; the operating
end of the operating shaft is provided with a generally flat
plate-shaped portion which is inserted into the cutout groove; the
shaft member is disposed so as to extend through the flat
plate-shaped portion; and the flat plate-shaped portion and the
cutout groove are caused to pivot relative to each other with
switch in the position of the operating knob.
14. The embroidery frame according to claim 8, wherein the
operating knob has both lengthwise ends each formed into a
generally convex semispherical shape.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from the prior Japanese Patent Application No. 2010-231505
filed on Oct. 14, 2010, the entire contents of which are
incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to an embroidery frame
including an outer frame and an inner frame and holding a workpiece
cloth between the outer and inner frames.
[0004] 2. Related Art
[0005] Conventional embroidery sewing machines comprise an
embroidery frame holding a workpiece cloth and an embroidery frame
transfer mechanism transferring the workpiece cloth. In the
embroidery sewing machines, a needle bar mechanism and other drive
mechanisms are controlled while the embroidery frame is transferred
in an X or a right-left direction and in a Y or front-back
direction, whereby an embroidery pattern is sewn on the workpiece
cloth.
[0006] The aforementioned embroidery frame includes an inner frame
generally formed into a rounded rectangularly annular shape, an
outer frame disposed outside the inner frame and generally formed
into a rectangular frame-shape and has a splitting section, and a
clamping mechanism which clamps the outer frame against the inner
frame. The clamping mechanism comprises a pair of screw-attachment
portions provided at both sides of the splitting section of the
outer frame respectively and an adjusting screw for connecting the
screw-attachment portions together. More specifically, one of the
screw-attachment portions or the right screw-attachment portion is
provided with an insertion hole through which a part of the
adjusting screw is inserted. The other or left screw-attachment
portion is provided with a nut with which a middle portion of the
adjusting screw is threadingly engaged. When a workpiece cloth is
set on the embroidery frame, an operator turns a head of the screw
to increase a width between the screw-attachment portions, placing
a workpiece cloth between the outer and inner frames. Next, the
operator turns the screw head in the opposite direction so that the
width between the screw-attachment portions is reduced. Thus, the
outer frame is fastened to the inner frame such that the workpiece
cloth is held between the outer and inner frames.
[0007] An embroidery frame having another clamping mechanism is
also known. This embroidery frame is provided with an operating
shaft which turns the adjusting screw of the clamping mechanism.
The operating shaft is coupled via a coupling mechanism with the
adjusting screw. The coupling mechanism couples the operating shaft
with the adjusting screw so that the adjusting screw is swingable.
When a workpiece cloth is set on the embroidery frame, the operator
swings or moves the operating shaft so that the operating shaft is
located at a position where the operator can easily operate the
operating shaft. Thereafter, the operator turns an operating
portion at a distal end of the operating shaft with his/her
fingertips, whereupon the adjusting screw can be turned.
[0008] In the above-described fastening mechanism, the adjusting
screw head or the operating portion of the operating shaft has a
relatively smaller outer diameter. Accordingly, some operators have
a difficulty in turning the adjusting screw or the operating shaft
with a sufficiently large force with the result that the outer
frame cannot be fastened tightly to the inner frame. In view of
this problem, it is considered to increase the outer diameter of
the adjusting screw head or the operating portion of the operating
shaft. However, when the outer diameter of the adjusting screw head
or the operating portion of the operating shaft is increased, the
adjusting screw head or the operating portion would contact a
sewing machine bed during a sewing operation of the embroidery
sewing machine. This would result in malfunction in transferring
the embroidery frame.
SUMMARY
[0009] Therefore, an object of the disclosure is to an embroidery
frame provided with an operating knob which turns the adjusting
screw of the fastening mechanism fastening the outer frame to the
inner frame and which can easily be turned with a smaller operating
force and can tightly fasten the outer frame to the inner
frame.
[0010] The present disclosure provides an embroidery frame which
holds a workpiece cloth, comprising an outer frame formed into a
substantially annular shape and having a discontinuity formed by
partially breaking the annularity of the outer frame so that the
outer frame has two ends located opposite each other with the
discontinuity being interposed therebetween, an inner frame
configured to be fitted with an inner periphery of the outer frame
so that the workpiece cloth is held between the outer and inner
frames, a clamping mechanism which clamps the outer frame against
the inner frame and includes a pair of screw-supporting members
provided on the ends of the outer frame respectively and an
adjusting screw which is mounted on the screw-supporting members so
as to be capable of adjusting a gap between the screw mounting
members, and an operating knob which is supported on an operating
end of the adjusting screw so as to be switchable between a first
position where the operating knob extends substantially in parallel
to an axial direction of the adjusting screw and a second position
where the operating knob extends in a direction substantially
perpendicular to the axial direction of the adjusting screw.
[0011] The disclosure also provides an embroidery frame which holds
a workpiece cloth, comprising an outer frame formed into a
substantially annular shape and having a discontinuity formed by
partially breaking the annularity of the outer frame so that the
outer frame has two ends located opposite each other with the
discontinuity being interposed therebetween, an inner frame
configured to be fitted with an inner periphery of the outer frame
so that the workpiece cloth is held between the outer and inner
frames, a clamping mechanism which clamps the outer frame against
the inner frame and includes a pair of screw-supporting members
provided on the ends of the outer frame respectively and an
adjusting screw which is mounted on the screw-supporting members so
as to be capable of adjusting a gap between the screw mounting
members, an operating shaft which rotates the adjusting screw and
is provided so as to be swingable between a first location where
central axes of the operating shaft and the adjusting screw extend
in an identical direction or a different direction and a second
location where the operating shaft is inclined in a direction such
that a space between the outer frame and the operating shaft is
increased, a coupling mechanism which couples the operating shaft
with the adjusting screw to transmit a rotational torque of the
operating shaft, and an operating knob which is supported on an
operating end of the operating shaft so as to be switchable between
a first position where the operating knob extends substantially in
parallel to an axial direction of the operating shaft and a second
position where the operating knob extends in a direction
substantially perpendicular to the axial direction of the operating
shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a plan view of an embroidery frame according to
one embodiment;
[0013] FIGS. 2A and 2B are enlarged plan views of a clamping
mechanism when an operating knob assumes first and second positions
respectively;
[0014] FIG. 3 is a longitudinal section of the clamping mechanism
taken along line III-III in FIG. 2A;
[0015] FIG. 4 is an enlarged cross-sectional view of the clamping
mechanism when the operating knob assumes the first position;
[0016] FIG. 5 is an enlarged cross-sectional view of the clamping
mechanism when the operating knob assumes the second position;
[0017] FIG. 6 is a perspective view of a sewing machine with the
embroidery frame being attached thereto;
[0018] FIG. 7 is a plan view of the embroidery frame according to a
second embodiment;
[0019] FIG. 8 is an enlarged plan view of the clamping
mechanism;
[0020] FIG. 9 is an enlarged front view of the clamping
mechanism;
[0021] FIG. 10 is an enlarged front view of the clamping mechanism
when the operating shaft has been swung to a second location;
[0022] FIG. 11 is an enlarged plan view of the clamping mechanism
when the operating knob assumes the second position;
[0023] FIG. 12 is an enlarged front view of the clamping mechanism
when the operating knob assumes the second position;
[0024] FIG. 13 is an enlarged longitudinally sectional front view
of the clamping mechanism when the operating knob assumes the first
position;
[0025] FIG. 14 is an enlarged cross-sectional plan view of the
clamping mechanism when the operating knob assumes the first
position;
[0026] FIG. 15 is an enlarged longitudinally sectional front view
of the clamping mechanism when the operating shaft is located at a
second position and the operating knob assumes the second
position;
[0027] FIG. 16 is a plan view of a part of a coupling
mechanism;
[0028] FIG. 17 is a front view of the part of the coupling
mechanism; and
[0029] FIG. 18 is an exploded perspective view of the clamping
mechanism.
DETAILED DESCRIPTION
[0030] A first embodiment will be described with reference to FIGS.
1 to 6. A sewing machine 1 capable of performing an embroidery
sewing will first be described. Referring to FIG. 6, the sewing
machine 1 includes a bed 2 extending in a right-left direction, a
pillar 3 extending upward from a right end of the bed 2 and an arm
4 extending leftward from an upper end of the pillar 3. The arm 4
has a distal end serving as a head 5. The side where an operator of
the sewing machine 1 is located will hereinafter be referred to as
"front" and the opposite side will be referred to as "back." The
side where the pillar 3 is located will be referred to as "right"
and the opposite side will be referred to as "left."
[0031] A needle bar 6 to which a needle (not shown) is attached is
mounted on the head 5 so as to be movable upward and downward. An
embroidery sewing presser foot 7 is also mounted on the head 5. The
bed 2 has an upper surface on which a needle plate (not shown) is
mounted so as to correspond to the needle bar 6. Below the needle
plate are provided a rotary hook which forms stitches in
cooperation with the needle and a hook mechanism driving the rotary
hook. In the arm 4 and the head 5 are provided a main shaft driven
by a sewing machine motor, a needle bar mechanism moving the needle
bar 6 upward and downward by drive of the main shaft and a needle
thread take-up mechanism moving a needle thread upward and downward
in synchronization with upward/downward movement of the needle bar
6.
[0032] An embroidery frame transfer device 8 is detachably attached
to a left end of the bed 2. The embroidery frame transfer device 8
includes a carriage to which an embroidery frame 10 holding a
workpiece cloth W is detachably attached. The embroidery frame 10
will be described in detail later. The sewing machine 1 further
includes a Y-direction transfer mechanism 9 transferring the
carriage (the embroidery frame 10) in the Y direction or the
front-back direction, an X-direction transfer mechanism (not shown)
transferring the Y-direction transfer mechanism 9 in the X
direction or the right-left direction. The embroidery frame 10 is
transferred in the X direction or the right-left direction and in
the Y direction or the front-back direction on the bed 2.
[0033] A plurality of key switches is provided on a front surface
of the arm 4. The key switches include a start/stop key 11
instructing start and stop of a sewing operation. A large
vertically long display device 12 is provided on the front of the
pillar 3. The display device 12 comprises a liquid crystal display
with a touch panel. The operator operates the touch panel to select
a desired one of a plurality of ordinary patterns and embroidery
patterns or to set a mode of sewing operation.
[0034] The embroidery frame 10 according to the embodiment will now
be described with reference to FIGS. 1 to 5 as well as FIG. 6. The
embroidery frame 10 includes a generally annular outer frame 13, an
inner frame 14 which is fitted with an inner periphery of the outer
frame 13 so that the workpiece cloth W is held therebetween, and a
clamping mechanism 15 which clamps the outer frame 13 against the
inner frame 14. The outer frame 13 is made of, for example, a resin
material and has four, that is, front, left, rear and right
continuous outer frame sides 13a to 13d located within a horizontal
plane. The outer frame 13 is formed into the shape of a rectangular
frame that is slightly elongate in the front-back direction and has
rounded corners. The left outer frame side 13b has a mounting
portion 16 which is formed integrally therewith so as to extend
leftward. The mounting portion 16 is connected to the carriage of
the embroidery frame transfer device 8. A discontinuity 17 is
defined by partially breaking the annularity of the outer frame 13
so as to be located between the outer frame sides 13a and 13d or at
a right front corner of the outer frame 13. The outer frame 13 is
provided with a pair of screw-supporting members 18 and 19 which
are located at both sides of the discontinuity 17 or more
specifically, at both ends of the outer frame 13 located opposite
each other, respectively. The screw-supporting members 18 and 19
constitute part of the clamping mechanism 15.
[0035] The inner frame 14 is also made of, for example, a resin
material and has four continuous inner frame sides 14a to 14d
formed integrally therewith and located within a horizontal plane.
The inner frame 14 is formed into the shape of a generally
rectangular frame and sized so as to be fitted with an inner
periphery of the outer frame 13. The inner frame sides 14a to 14d
have ribs 14e formed integrally on inner peripheral edges
respectively. The inner frame 14 is thus reinforced by the ribs 14e
in order to be prevented from deformation due to an external
force.
[0036] The clamping mechanism 15 is provided with the paired
screw-supporting members 18 and 19 and an adjusting screw 20 as
shown in FIGS. 2A, 2B and 3 as well as in FIG. 1. The
screw-supporting members 18 and 19 are formed so as to protrude
outward from a right end of the outer frame side 13a and a front
end of the outer frame side 13d, that is, in parallel right
diagonally forward. The screw-supporting members 18 and 19 are
opposed to each other at both sides of the discontinuity 17. The
adjusting screw 20 is used to adjust a distance between the
screw-supporting members 18 and 19 and extends through the
screw-supporting members 18 and 19. The adjusting screw 20 is made
of a metal material and has a right proximal end (an operating end
side) on which an operating knob 25 is mounted as shown in FIG. 3.
The adjusting screw 20 further has a larger-diameter portion 20a
located on the left of the operating knob 25 and a smaller-diameter
shaft portion located on the left of the larger-diameter portion
20a. The shaft includes a part which excludes a proximal end side
(a right end side) and serves as a male screw 20b formed with a
male thread.
[0037] The screw-supporting member 18 located on the left as viewed
in FIG. 3 has an insertion hole 18a which is formed so as to extend
therethrough in the right-left direction. The shaft portion of the
adjusting screw 20 has a distal end which is adapted to extend
through the insertion hole 18a. Accordingly, the insertion hole 18a
has a larger diameter than an external diameter of the shaft
portion. The screw-supporting member 18 has a circular hole 18b
formed in a central portion thereof so as to vertically extend
therethrough as shown in FIGS. 2A and 2B. A columnar nut member 22
is inserted into the circular hole 18b. The nut member 22 is formed
with a screw hole 22a which horizontally extends so as to be
continuous to the insertion hole 18a, as shown in FIG. 3. The
adjusting screw 20 has a male thread 20b threadingly engaging the
screw hole 22a.
[0038] The screw-supporting member 19 located in the right as
viewed in FIG. 3 has a circular hole 19c which is located in the
middle thereof and vertically extends therethrough, as shown in
FIG. 3. The screw-supporting member 19 further has an insertion
hole 19a which is located on the left of the circular hole 19c and
extends horizontally (in the right-left direction) and an insertion
hole 19b which is located on the right of the circular hole 19c and
extends horizontally (in the right-left direction in FIG. 3). The
circular hole 19b has a larger diameter than the insertion hole
19a. The insertion hole 19a has an inner diameter sufficient for
the shaft portion of the adjusting screw 20 (a part having no male
thread) to extend therethrough. The insertion hole 19b has an inner
diameter sufficient for the larger-diameter portion 20a of the
adjusting screw 20 to extend therethrough.
[0039] A columnar stopper 23 is fixed in the circular hole 19c. The
stopper 23 extends horizontally (in the right-left direction in
FIG. 3) and has a through hole 23a through which the shaft portion
of the adjusting screw 20 is to extend. The adjusting screw 20 is
inserted through the through hole 19b, the through hole 23a of the
stopper 23, the through hole 19a and the through hole 18a of the
screw-supporting member 18. The male thread 20b is screwed into the
screw hole 22a of the nut member 22. In this case, the adjusting
screw 20 is positioned relative to the screw-supporting member 19
so that the larger-diameter portion 20a of the adjusting screw 20
abuts the stopper 23. A spring serving as a biasing member is
fitted between the screw-supporting members 18 and 19 in such a
manner that a gap is defined around the male thread 20b of the
adjusting screw 20. The screw-supporting members 18 and 19 are
biased by an elastic force of the spring 21 in such respective
directions that the screw-supporting members 18 and 19 depart from
each other or that the distance therebetween is increased.
[0040] When the adjusting screw 20 is turned clockwise, the male
thread 20b is screwed into the screw hole 22a of the nut member
relative to the adjusting screw 20 such that the screw-supporting
member 18 is moved so as to come closer to the screw-supporting
member 19, whereupon the inner peripheral surface of the outer
frame 13 is clamped in such a direction that an inner diameter of
the outer frame 13 is reduced. When the adjusting screw 20 is
turned counterclockwise, the male thread 20b is moved in such a
direction that the male thread 20b is relatively dropped out of the
screw hole 22a of the nut member 22, whereby the screw-supporting
member 18 is moved so as to depart from the screw-supporting member
19. In this case, an elastic force of the spring 21 increases the
distance between the screw-supporting members 18 and 19. In other
words, since the inner peripheral surface of the outer frame 13 is
rendered larger, the clamping force against the inner frame 14 is
reduced. The operating knob 25 is provided on the proximal end of
the adjusting screw 20. In the embodiment, the operating knob 25 is
switchable between a first position (see FIGS. 2A and 4) where the
operating knob 25 extends in substantially the same direction as
the axial direction of the adjusting screw 20 and a second position
(see FIGS. 2B and 5) where the operating knob 25 extends in the
direction perpendicular to the axial direction of the adjusting
screw 20.
[0041] The operating knob 25 and its circumjacent structure will
now be described with reference to FIGS. 4 and 5 as well as FIG. 1.
The adjusting screw 20 has a flat plate-shaped portion 24 formed
integrally with the proximal end thereof adjacent to the
larger-diameter portion 20a. The flat plate-shaped portion 24 is
horizontally flat as shown in FIG. 3. The operating knob 25 is
mounted to the flat plate-shaped portion 24. The operating knob 25
is made of a metal material and formed into the shape of a circular
column (or a rounded bar) elongate in the right-left direction as
viewed in FIG. 3. The operating knob 25 includes two lengthwise
ends each formed into a convex semispherical shape and a knurled
portion 25a (see FIGS. 2A and 2B) provided in an outer peripheral
surface excluding both ends thereof. The operating knob 25 has a
cutout groove 26 which is formed substantially in a partial central
part thereof as shown in FIGS. 4 and 5. The cutout groove 26 has a
first wall 26a formed on the longer side and a second wall 26b
formed on the shorter side. The cutout groove 26 has a width such
that the flat plate-shaped portion 24 of the adjusting screw 20 is
insertable thereinto.
[0042] The operating knob 25 has a stepped hole 27 which is formed
substantially in the lengthwise middle thereof so as to vertically
extend through the operating knob 25 and so as to be generally
perpendicular to the cutout groove 26 as shown in FIG. 3. A stepped
screw 28 serving as a shaft member is inserted into the stepped
hole 27. The flat plate-shaped portion 24 has a threaded hole 24a
which is formed at the distal end side so as to correspond to the
stepped hole 27 as shown in FIGS. 4 and 5. The stepped hole 27
includes a stepped portion 27a, a larger diameter portion located
higher than the cutout groove 26 and an intermediate diameter
portion located higher than the cutout groove 26, as shown in FIG.
3. A stepped screw 28 corresponds to the stepped hole 27 and the
screw hole 24a of the flat plate-shaped portion 24 and has a distal
end (a lower end in FIG. 3) formed into a smaller diameter portion.
The stepped screw 28 also has a middle portion formed into a
threaded portion 28b which is engageable with the screw portion
28b, an intermediate diameter portion and an upper end formed into
a head 28a which is accommodated in the upper portion or the larger
diameter portion of the stepped portion 27a. The head 28a of the
stepped screw 28 is formed with a slot into which a flat-blade
screwdriver (not shown) is inserted to be driven so that the
stepped screw 28 is fixed to the flat plate-shaped portion 24.
[0043] When the operating knob 25 is mounted to the flat
plate-shaped portion 24 of the adjusting screw 20, the flat
plate-shaped portion 24 is inserted into the cutout groove 26. The
stepped screw 28 is inserted into the stepped hole 27 from above as
shown in FIG. 3 after the stepped hole 27 has been aligned with the
screw hole 24a. The threaded portion 28b of the stepped screw 28 is
then threadingly engaged with the threaded hole 24a of the flat
plate-shaped portion 24 thereby to be fixed in position. The
operating knob 25 is then rotatably supported on the flat
plate-shaped portion 24. In this case, an annular wave spring 29
serving as a retaining member is attached in a compressed state
between the head 28a of the stepped screw 28 and the stepped
portion 27a of the stepped hole 27.
[0044] The operating knob 25 is switchable (pivotable) between the
first and second positions as described above. When the operating
knob 25 assumes the first position as shown in FIGS. 2A and 4, one
side of the flat plate-shaped portion 24 abuts the first wall 26a
such that the operating knob 25 extends substantially in the same
direction as the axial direction of the adjusting screw 20. When
the operating knob 25 assumes the second position as shown in FIGS.
2B and 5, another side of the flat plate-shaped portion 24 abuts
the second wall 26b such that the operating knob 25 extends in the
direction perpendicular to the axial direction of the adjusting
screw 20. Thus, the operating knob 25 is configured to pivot about
90.degree.. When the operating knob 25 assumes the second position,
the adjusting screw 20 of the flat plate-shaped portion 24 and the
operating knob 25 are arranged substantially into a T-shape. With
the switching in the position of the operating knob 25, the flat
plate-shaped portion 24 and the cutout groove 26 pivot relative to
each other. Since the wave spring 29 is attached in the compressed
state, a resistive force of friction is imparted to the operating
knob 25 when the operating knob 25 is caused to pivot. The
operating knob 25 is thus retained in the first or second position
by the resistive force of friction.
[0045] The embroidery frame 10 as constructed above will work as
follows. When the workpiece cloth W is to be set on the embroidery
frame 10, the operator firstly places the outer frame 13 on a work
table (not shown) as shown in FIG. 1. In this case, the operating
knob 25 is retained in the first position, and the distance between
the screw-supporting members 18 and 19 is maintained in an
increased state to some extent. The operating knob 25 is located
slightly above the underside of the outer frame 13 when assuming
the first position, as shown in FIG. 3. Accordingly, the operating
knob 25 is prevented from contact with the work table. The operator
next puts the workpiece cloth W on the upper side of the outer
frame 13 while aligning the workpiece cloth W with the outer frame
13. More specifically, the operator puts the workpiece cloth W on
the outer frame 13 so that an embroidery pattern to be sewn is
located substantially at the center of the outer frame 13. The
operator presses the workpiece cloth W downward from above while
aligning the inner frame 14 so that the inner frame 14 is fitted
with the inner periphery of the outer frame 13. The inner frame 14
is fitted with the inner periphery of the outer frame 13 such that
the workpiece cloth W is pressed into the inner peripheral side of
the outer frame 13, whereupon the workpiece cloth W is held between
the inner periphery of the outer frame 13 and the outer periphery
of the inner frame 14.
[0046] The operator then brings the embroidery frame 10 slightly
upward and grips the operating knob 25 with his/her fingertips to
turn the operating knob 25 clockwise (in the direction of arrow B
in FIG. 2B). As a result, the adjusting screw 20 is turned
clockwise such that screw-supporting members 18 and 19 are moved so
that the distance therebetween is reduced or narrowed. The outer
frame 13 can be clamped against the inner frame 14 in the
above-described manner. However, since the outer diameter of the
operating knob 25 is small when the operating knob 25 assumes the
first position, the operator has a difficulty in turning the
operating knob 25 with a sufficiently large force. Hence, the
operator causes the operating knob 25 to pivot about the stepped
screw 28 about 90.degree. in the direction of arrow A shown in
FIGS. 2A and 4. As a result, the operating knob 25 is switched from
the first position as shown in FIGS. 2A and 4 to the second
position as shown in FIGS. 2B and 5. The operator turns the
operating knob 25 clockwise at his/her fingertips after having
switched the operating knob 25 into the second position. When the
operating knob 25 assumes the second position, the outer diameter
of the operating knob 25 is increased. Accordingly, the torque for
turning the adjusting screw 20 can be increased even though an
operating force which turns the operating knob 25 is small. As a
result, the operator can easily turn the operating knob 25 and
accordingly the adjusting screw 20 with a small operating force,
whereupon the outer frame 13 can be tightly clamped against the
inner frame 14. The operator then plucks the outer edge (not shown)
of the workpiece cloth W outward to tighten the workpiece cloth
W.
[0047] After the outer frame 13 has been clamped, the operator
causes the operating knob 25 to pivot to return the operating knob
25 from the second position to the first position. Subsequently,
the operator attaches the embroidery frame 10 holding the workpiece
cloth W to the carriage of the embroidery frame transfer device 8
for execution of an embroidery sewing operation. Since the
operating knob 25 assumes the first position in this case, the
operating knob 25 can be prevented from contact with the bed 2
during the sewing of an embroidery pattern.
[0048] Upon completion of the embroidery sewing operation, the
operator detaches the embroidery frame 10 from the embroidery frame
transfer device 8, further detaching the workpiece cloth W from the
embroidery frame 10. In detachment of the workpiece cloth W, the
operating knob 25 is turned counterclockwise so that the distance
between the screw-supporting member 18 and 19 is increased. As a
result, the clamping force the outer frame 13 imparts to the inner
frame 14 is reduced such that the inner frame 14 can be detached
from the outer frame 13. In this case, too, the operator can easily
turn the adjusting screw 20 with a small operating force when the
operator switches the operating knob 25 to the second position.
[0049] According to the above-described embroidery frame 10, the
clamping mechanism 15 clamping the outer frame 13 against the inner
frame 14 includes the operating knob 25 which is mounted on the
proximal end of the adjusting screw 20 so as to be switchable
between the first and second positions. Since the operating knob's
assuming the second position is equivalent to increasing the outer
diameter of the operating knob 25, the torque turning the adjusting
screw 20 can be increased even though the operating force to turn
the operating knob 25 is small. Accordingly, the operator can
easily turn the operating knob 25 with a small operating force to
tightly clamp the outer frame 13 against the inner frame 14. When
the operating knob 25 is returned to the first position, the
embroidery frame 10 can properly be transferred by the embroidery
frame transfer device 8 without the operating knob 25 contacting
the bed 2 during the sewing.
[0050] The stepped screw 28 and the wave spring 29 are used as a
supporting structure for the adjusting screw 20. As a result, the
supporting structure is simplified, and the operator can easily
switch the position of the operating knob 25. The operator can
easily turn the operating knob 25 since the adjusting screw 20 and
the operating knob 25 are arranged substantially into the T-shape
or are substantially perpendicular to each other when the operating
knob 25 assumes the second position. In this case, the operating
knob 25 can be retained in the first and second positions by the
frictional resistive force of the wave spring 29. Consequently, the
departure of the operating knob 25 from the second position can be
suppressed when the operator turns the operating knob 25. The
departure of the operating knob 25 from the first position can also
be suppressed during the sewing.
[0051] The flat plate-shaped portion 24 located at the operation
side end of the adjusting screw 20 is disposed in the cutout groove
26 of the operating knob 25 in the embodiment. Consequently, the
operating knob 25 can compactly be disposed. Furthermore, the
operating force applied to the operating knob 25 can reliably be
transmitted to the adjusting screw 20 by a relatively simpler
structure. Still furthermore, the pivot range of the operating knob
25 can be limited by the abutment of the first or second wall 26a
or 26b of the cutout groove 26 against the flat plate-shaped
portion 24. Additionally, the operating knob 25 has both lengthwise
ends formed into respective convex semispherical shapes.
Consequently, a good operational feeling can be obtained when the
operator pinches the operating knob 25 with his/her fingertips to
operate the knob.
[0052] A second embodiment will be described with reference to
FIGS. 7 to 18. The second embodiment differs from the first
embodiment in the construction of the clamping mechanism 35. In the
second embodiment, an operating shaft 39 is provided for turning
the adjusting screw 38 and the operating knob 54 is mounted on the
operation side end of the operating shaft 39, instead of the direct
provision of the operating knob on the proximal end of the
adjusting screw. The identical or similar parts in the second
embodiment are assigned with the same reference symbols as those in
the first embodiment and detailed description of these parts will
be eliminated. Only the difference between the first and second
embodiments will be described.
[0053] The embroidery frame 30 according to the second embodiment
has the outer and inner frames 31 and 32 each of which is formed
substantially into a rectangular annular shape. Each frame is made
of a resin material. The inner frame 32 is fitted with the inner
periphery of the outer frame 31 such that the workpiece cloth W is
held between the outer and inner frames 31 and 32. The outer frame
31 has four, that is, front, left, rear and right frame sides 31a
to 31d located within a horizontal plane. The left frame side 31b
has a mounting portion 33 which is formed integrally on the middle
thereof so as to extend leftward. The mounting portion 33 is to be
coupled to the carriage of the embroidery frame transfer device 8.
The disconnection section 34 is defined in the center of the front
outer frame side 31a so as to break continuity of the outer frame
31. The disconnection section 34 is provided with the clamping
mechanism 35 for clamping the outer frame 31 against the inner
frame 32. The inner frame 32 has four inner frame sides 32a to 32d
located within a horizontal plane and ribs 32e formed on inner
peripheral edges of the inner frame sides 32a to 32d
respectively.
[0054] The clamping mechanism 35 will now be described in detail
with reference to FIGS. 8 to 18. The clamping mechanism 35 includes
a pair of screw-attached portions 36 and 37, an adjusting screw 38,
an operation shaft 39, a coupling mechanism 40, a pivoting
mechanism 41 and an operating knob 54. The screw-attached portions
36 and 37 are formed integrally with the outer frame side 31a so as
to be located at right and left sides of the split section 34
respectively and so as to protrude frontward from the outer frame
side 31a. The screw-attached portions 36 and 37 are opposed to each
other and has respective through insertion holes 36a and 37a
extending horizontally or in the right-left direction as shown in
FIG. 14. The left screw-attached portion 36 has a circular hole 36b
extending vertically. A columnar nut member 42 is inserted into the
circular hole 36b. The nut member 42 is formed with a screw hole
42a which extends in the right-left direction so as to continue to
the insertion hole 36a.
[0055] The adjusting screw 38 includes a head 38a located at the
proximal end (a right end as viewed in FIG. 14) thereof, a shaft
38b extending leftward from the head 38a and a male thread 38c
located at the distal end side. The distal end of the adjusting
screw 38 is inserted through the insertion holes 37a and 36a in
turn from the right to be threadingly engaged with the male thread
38c of the screw hole 42a of the nut member 42. The head 38a is
formed into the shape of a cylinder with a right open end and is
located on the right outer wall of the screw attachment portion 37.
The shaft 38b is inserted through the insertion hole 37a thereby to
be rotatably supported. A pair of washers 43 and 44 and a stop ring
45 are fitted with the shaft 38b so as to abut the right and left
outer walls of the screw attachment portion 37 respectively. When
the adjusting screw 38 is turned clockwise, the paired screw
attachment portions 36 and 37 are moved such that the distance
therebetween is narrowed or reduced. When the adjusting screw 38 is
turned counterclockwise, the screw attachment portions 36 and 37
are moved such that the space therebetween is expanded or
increased.
[0056] The following will describe a coupling mechanism 40 which
transfers rotary torque of the operating shaft 39 to the adjusting
screw 38. The head 38a of the adjusting screw 38 is formed with a
coupling hole 46 having an open end (a right end as viewed in FIGS.
13 and 14). The open end of the coupling hole 46 is formed into an
inverse tapered shape with the right opening side having a larger
diameter. The coupling hole 46 has an inner peripheral wall formed
with a pair of slits 47 (see FIGS. 17 and 18) extending axially
with respect to the adjusting screw 38. The operating shaft 39 has
a distal end 39a having a smaller diameter than the coupling hole
46 thereby to be inserted into the coupling hole 46 with a space
being defined therebetween. An engagement pin 48 is inserted
through a hole formed in the distal end 39a so as to be slidable
and so as to be perpendicular to the central axis as shown in FIG.
16 as well as in FIG. 14. The engagement pin 48 has both ends
slidably engaged with the slits 47 respectively such that the
operating shaft 39 is coupled to the adjusting screw 38.
[0057] The operating shaft 39 is turnable about the shaft center,
and the torque is transmitted from the distal end 39a of the
operating shaft 39 via the engagement pin 48 to the head 38a of the
adjusting screw 38. Since the distal end 39a of the operating shaft
39 is slidably in engagement with the slits 47, the engagement pin
48 is rotatable or swingable about the engagement pin 48 relative
to the head 38a. Thus, the coupling mechanism 40 functions as a
universal joint which is capable of transmitting the rotary torque
to the adjusting screw 38 even when the operating shaft 39 is
turned to be inclined at any inclination. A cylindrical cover
sleeve 49 (see FIG. 18) made of a resin is attached to the head 38a
of the adjusting screw 38 in order that the engagement pin 48 may
be prevented from dropping off the distal end 39a of the operating
shaft 39.
[0058] A pivotably supporting mechanism 41 shown in FIGS. 11 and 14
pivotably supports the operating shaft 39 on the outer frame 31.
The operating shaft 39 is further mounted on the adjusting screw 38
so to be swingable about the shaft center of the adjusting screw 38
via the coupling mechanism 40 and the pivotably supporting
mechanism 41. The operating shaft 39 is swingable between a first
location (the location as shown in FIG. 9) where the shaft centers
of the operating shaft 39 and the adjusting screw 38 are directed
in the same direction and a second location (the location as shown
in FIG. 10) where the gap between the operating shaft 39 and the
outer frame 31 is rendered larger or increased. The first location
may be determined such that the shaft centers of the operating
shaft 39 and the adjusting screw 38 are slightly displaced from
each other.
[0059] A pivotably supporting hardware 50 is fixed closely to the
underside of the outer frame 31 by a pair of screws 51 as shown in
FIGS. 8, 11, 14 and 18. The pivotably supporting hardware 50
includes a base 50a, a pivotably supporting portion 50b and a
stopper 50c. The base 50a is fixed to the outer frame 31 (the right
screw attachment portion 37) by a screw 51, and the pivotably
supporting portion 50b rises vertically from the base 50a. The
stopper 50c protrudes from an end of the base 50a thereby to limit
a swinging range of the operating shaft 39.
[0060] A coupler 52 made of a resin is fitted with an outer
periphery of the shaft 39b of the operating shaft 39 as shown in
FIGS. 13 and 15. The generally semicylindrical coupler 52 has a
centrally located coupling hole 52a into which the operating shaft
39 is inserted. The coupler 52 is prevented by a stepped portion
39c and a stop ring 55 from being axially moved relative to the
operating shaft 39. The operating shaft 39 is rotatably inserted
through the coupler 52. The operating shaft 39 is supported by a
support arm 56. The operating shaft 39 has a flat plate-shaped
portion 53 formed integrally on the right proximal end thereof as
viewed in FIG. 13 (an operation side end). An operating knob is
attached to the flat plate-shaped portion 53. The operating knob 54
will be described in detail later.
[0061] The support arm 56 is formed from a bent metal plate. The
operation side end of the support arm 56 is inserted into an inner
groove (see FIG. 18) of the coupler 52 to be fixed via a
rectangular plate-shaped washer 57 by a screw 58. The other end of
the support arm 56 is pivotably supported on the pivotably
supporting portion 50b of the hardware 50 by a stepped pin 59 so as
to be in parallel to the central axis of the adjusting screw 38.
The central axis of the adjusting screw 58 is perpendicular to a
central axis of the adjusting screw 38.
[0062] The operating shaft 39 is pivotable about the stepped pin
59. The operating shaft 39 is swingable between a first location
(as shown in FIG. 9) where the operating shaft 39 assumes a
horizontal position and a second location (as shown in FIG. 10)
where the operating shaft 39 is upwardly inclined. The operating
shaft 39 assuming the horizontal position is in parallel to the
outer frame side 31a. When the operating shaft 39 assumes the
second location, a clearance between the outer frame 31 and the
operating shaft 39 and a clearance between the a horizontal plane
inclusive of the underside of the inner frame 32 and the operating
shaft 39 are increased.
[0063] A wave spring (not shown) is attached between a head 59a of
the stepped pin 59 and the support arm 56. The wave spring applies
a frictional resistance force to the operation side end of the
support arm 56 when the operation side end pivots, so that the
operating shaft 39 can be supported at any location which is
located between a first location and a second location and includes
the first and the second locations. When located at the first
location, the operating shaft 39 is received from below by the
stopper 50c of the pivotably supporting hardware 50, whereupon a
range of swinging movement of the operating shaft 39 is
limited.
[0064] The operating knob 54 located at the proximal end of the
operating shaft 39 is provided so as to be changeable between the
first location and the second location in the second embodiment.
When assuming the first location, the operating knob 54 extends
substantially in the axial direction of the operating shaft 39 (see
FIGS. 8 to 10). When assuming the second location, the operating
knob 54 extends in a direction crossing the axial direction of the
operating shaft 39 or a direction perpendicular to the axial
direction of the operating shaft 39 in this case (see FIGS. 11 and
12).
[0065] The construction of the operating knob 54 will be described
with reference to FIGS. 13 to 18 as well as to FIGS. 7 to 12. The
proximal end (a portion located nearer the distal end side than the
stepped portion 39c) of the operating shaft 39 is provided with the
flat plate-shaped portion 53 formed integrally therewith. The
operating knob 54 is mounted on the flat plate-shaped portion 53.
The operating knob 54 is made of a metal material and is formed
into a columnar shape elongate in the right-left direction as
viewed in FIGS. 9 and 13. the operating shaft 39 and the operating
knob 54 are positioned so as to generally form a T-shape when the
operating knob 54 assumes the second location. The flat
plate-shaped portion 53 and the cutout groove 60 are caused to
pivot relative to each other with the change in the location of the
operating knob 54. In this case, since the wave spring 63 is
attached in the compressed state, a frictional resistance force is
imparted to the operating knob 54 by the wave spring 63. The
operating knob 54 is held in the first or second location by the
frictional resistance force. The operating knob 54 has a knurling
54a (see FIGS. 9 and 10) formed on a peripheral surface thereof
except for both ends. The operating knob 54 also has a cutout
groove 60 which is formed in a part thereof so as to substantially
extend along a central axis thereof, as shown in FIGS. 13 and 14.
The cutout groove 60 has a long side first wall 60a and a short
side second wall 60b. The cutout groove 60 has a width such that
the flat plate-shaped portion 53 is insertable thereinto.
[0066] The operating knob 54 has a stepped hole 61 formed through a
lengthwise central portion thereof so as to vertically extend
therethrough in perpendicular to the cutout groove 60 as viewed in
FIG. 14. A stepped screw 62 serving as a shaft member is inserted
through the stepped hole 61. The flat plate-shaped portion 53 has a
screw hole 53a formed in the distal end side thereof so as to
correspond to the stepped hole 61. The stepped hole 61 includes an
intermediate diameter portion and a larger diameter portion both
located below the cutout groove 60. The stepped hole 61 includes a
stepped portion which is formed on the surface side so as to be
adjacent to the larger diameter portion. The stepped screw 62
corresponds to the stepped hole 61 and a screw hole 53a of the flat
plate-shaped portion 53. The stepped screw 62 has a distal end
formed with a smaller diameter portion, a middle portion formed
with a thread portion 62b threadingly engaged with the screw hole
53a, and a lower side formed with a head 62a which is adapted to be
accommodated in the stepped portion 61a. The head 62a of the
stepped screw 62 is formed with a groove into which a straight slot
screwdriver is to be inserted in order that the stepped screw 62 is
fixed to the flat plate-shaped portion 53.
[0067] When the operating knob 54 is to be mounted to the flat
plate-shaped portion 53 of the operating shaft 39, the flat
plate-shaped portion 53 is inserted into the cutout groove 60 of
the operating knob 54 so that the stepped screw 61 is aligned to
the screw hole 53a. The stepped screw 62 is inserted into the
stepped hole 61 from the front side as viewed in FIG. 14 (a lower
part of the plane of paper), so that the thread portion 62b of the
stepped screw 62 is threadingly engaged with the thread hole 53a of
the flat plate-shaped portion 53 thereby to be fixed. As a result,
the operating knob 54 is pivotably mounted on the flat plate-shaped
portion 53. In this case, an annular wave spring 63 (see FIG. 18)
serving as a supporting member is attached between the head 62a of
the stepped screw 62 and the stepped portion 61a of the stepped
hole 61 in a compressed state.
[0068] When the operating knob 54 assumes the first position, one
side of the flat plate-shaped portion 53 abuts the first wall 60a,
thereby extending substantially in the same direction as the axial
direction of the operating knob 39, as shown in FIG. 13. When the
operating knob 54 assumes the second position, the opposite side of
the flat plate-shaped portion 53 abuts the second wall 60b, thereby
extending in the direction crossing the axial direction of the
operating knob 39, as shown in FIG. 15. The operating knob 54 is
thus configured to pivot about 90.degree., and the operating shaft
39 and the operating knob 54 are positioned so as to form a
generally T-shaped arrangement when the operating knob 54 assumes
the second position. The flat plate-shaped portion 53 and the
cutout groove 60 are caused to pivot relative to each other with
the change in the position of the operating knob 54. In this case,
since the wave spring 63 is attached in the compressed state, a
frictional resistance force is imparted to the operating knob 54 by
the wave spring 63. The operating knob 54 is held in the first or
second position by the frictional resistance force.
[0069] The embroidery frame 30 according to the second embodiment
will work as follows. When setting the workpiece cloth W to the
embroidery frame 30, the operator places the outer frame 31 on a
work table (not shown) as shown in FIG. 7. In this case, the
operating shaft 39 is set to the first location and the operating
knob 54 is set to the first position. The distance between the
screw-attached portions 36 and 37 of the outer frame 31 is kept
increased to some extent. When the operating shaft 39 is located at
the first location and the operating knob 54 assumes the first
position, the operating knob 54 is located slightly above the
underside of the outer frame 31 as shown in FIG. 9. As a result,
the operating knob 54 is prevented from contact to the work table.
The operator then puts the workpiece cloth W onto the upper side of
the outer frame 31 while aligning the workpiece cloth W to the
outer frame 31. More specifically, the operator puts the workpiece
cloth W on the outer frame 31 so that a part of the workplace cloth
W where an embroidery patterns is to be sewn is located
substantially at the center of the outer frame 31. The operator
presses the upper side of the workpiece cloth W downward while
aligning the inner frame 32 so that the inner frame 32 is fitted
with the inner periphery of the outer frame 31. Thus, the inner
frame 32 is fitted with the inner periphery such that the workpiece
cloth W is pressed to the inner peripheral side of the outer frame
31 thereby to be held between the inner and outer frames 32 and
31.
[0070] Subsequently, the operator pinches the operating knob 54
with his/her fingertips and swings the operating shaft 39 in the
direction of arrow C from the first location as shown in FIG. 9 so
that the operating shaft 39 occupies the second location where the
distance between the operating shaft 39 and the outer frame 31 is
increased, as shown in FIG. 10. Subsequently, the operator causes
the operating knob 54 to pivot from the first position as shown in
FIG. 10 in the direction of arrow D until the operating knob 54
assumes the second position as shown in FIGS. 11 and 12.
[0071] The operator then pinches the operating knob 54 with his/her
fingertips to turn the operating knob 54 clockwise (in the
direction of arrow F in FIG. 12). Turn of the operating knob 54 is
transmitted via the operating shaft 39 and the coupling mechanism
40 to the adjusting screw 38, which is then turned clockwise so
that the screw attachment portions 36 and 37 are moved such
respective directions as to reduce the distance therebetween. As a
result, the outer frame 31 can tightly be clamped against the inner
frame 32. However, since the outer diameter of the operating knob
54 is small in the case where the operating knob 54 assumes the
first position, it is difficult for the operator to turn the
operating knob 54 with a sufficiently large force. Thereupon, the
operator causes the operating knob 54 to pivot about the stepped
screw 54 by 90.degree. in the direction of arrow D in FIG. 10. As a
result, the operating knob 54 is changed from the first position as
shown in FIG. 10 to the second position as shown in FIG. 12.
[0072] After having switched the operating knob 54 to the second
position, the operator pinches the operating knob 54 with his/her
fingertips to turn the knob 54 clockwise. Since the condition where
the operating knob 54 assumes the second position corresponds to
the increased outer diameter of the operating knob 54, the torque
turning the adjusting screw 38 can be increased even though the
operating force to turn the operating knob 54 is small. Thus, the
operator can easily turn the operating knob (the adjusting screw
38) with the small operating force, whereupon the outer frame 31
can tightly be clamped against the inner frame 32. In this case,
the operator pulls the outer edge of the workpiece cloth W outward
to eliminate slack of the workpiece cloth W.
[0073] The operator causes the operating knob 54 to pivot thereby
to return the operating knob 54 from the second position to the
first position after having completed the clamping of the outer
frame 31. The operator then swings the operating knob 54 downward
(in the direction opposite arrow C in FIG. 9) to return the
operating shaft 39 from the second location to the first location.
Subsequently, the operator attaches the embroidery frame 30 holding
the workpiece cloth W to the carriage of the embroidery frame
transfer device 8, then executing the embroidery sewing operation.
Since the operating shaft 39 occupies the first location and the
operating knob 54 assumes the first position, the operating knob 54
can be prevented from contacting the bed 2 during the sewing of the
embroidery pattern.
[0074] Upon completion of the embroidery sewing operation, the
operator detaches the embroidery frame 30 from the embroidery frame
transfer device 8, further detaching the workpiece cloth W from the
embroidery frame 30. In detachment of the workpiece cloth W from
the embroidery frame 30, the operating knob 54 is turned
counterclockwise so that the distance between the screw-attached
portions 36 and 37 is increased, whereby the outer frame 31 is
unclamped. As a result, the inner frame 32 can be detached from the
outer frame 31. In this case, too, the operator swings the
operating shaft 39 to the second location and switches the
operating knob 54 to the second position to operate the operating
knob 54. Consequently, the operating knob 54 or the adjusting screw
38 can easily be turned with a smaller operating force.
[0075] According to the above-described embroidery frame 30, the
clamping mechanism 35 which clamps the outer frame 31 against the
inner frame 32 includes the operating shaft 39 which is swingable
between the first and second locations. Furthermore, the operating
knob 54 provided on the proximal end of the operating shaft 39 is
switchable between the first and second positions. Since the
condition where the operating knob 54 assumes the second position
corresponds to the increased outer diameter of the operating knob
54, the torque turning the adjusting screw 38 can be increased even
though the operating force to turn the operating knob 54 is small.
Thus, the operator can easily turn the operating knob 54 (the
adjusting screw 38) with the small operating force, whereupon the
outer frame 31 can tightly be clamped against the inner frame 32.
When the operator returns the operating knob 54 to the first
position and further returns the operating shaft 39 to the first
position, the embroidery frame 30 can properly be transferred by
the embroidery frame transfer device 8 without contact of the
operating knob 54 with the bed 2 during the sewing operation.
[0076] In the embodiment, the stepped screw 62 and the wave spring
63 are used as the structure for supporting the operating knob 54
on the operating shaft 39. Accordingly, the supporting structure
for the operating knob 54 is simple such that the operator can
easily change the position of the operating knob 54. When the
operating knob 54 assumes the second position, the operating shaft
39 and the operating knob 54 are positioned so as to form a
generally T-shaped arrangement or so as to be substantially
perpendicular to each other. Consequently, the operator can easily
turn the operating knob 54.
[0077] The operating knob 54 is held at the first or second
position by the frictional resistance force of the wave spring 63.
Accordingly, when the operator turns the operating knob 54,
displacement of the operating knob 54 from the second position can
be suppressed, and displacement of the operating knob 54 from the
first position can be suppressed.
[0078] In the embodiment, the operating knob 54 can be disposed in
a compact manner since the flat plate-shaped portion 53 of the
operation side end of the operating shaft 39 is disposed in the
cutout groove 60 of the operating knob 54. Furthermore, the
operating force of the operating knob 54 can reliably be
transmitted to the adjusting screw 38 by a relatively simpler
structure. When the flat plate-shaped portion 53 abuts the first or
second wall 60a or 60b of the cutout groove 60, the range of
pivotal movement of the operating knob 54 can be limited.
[0079] In the embodiment, the operating knob 54 has both lengthwise
ends formed into respective convex semispherical shapes.
Consequently, a good operational feeling can be obtained when the
operator pinches the operating knob 25 with his/her fingers to
operate the knob.
[0080] The above-described embodiments should not be restrictive
but may be expanded or modified as follows. Although the embroidery
frame 10 or 30 is formed into a substantially rectangular frame
shape in the foregoing embodiments, the embroidery frame may be
formed into a circular or elliptic shape, instead. In each
foregoing embodiment, the operating knob 25 or 54 is formed with
the cutout groove 26 or 64 into which the flat plate-shaped portion
24 or 53 is inserted and supported by the stepped screw 28 or 62
serving as the shaft member. However, the above-described
construction may be changed into any form only if the operating
knob 25 or 54 is pivotably supported on the adjusting screw 20 or
the operating shaft 39. Although the operating knob 25 or 54 is
pivotable about the stepped screw 28 or 62 by about 90.degree. in
the foregoing embodiments, the angle of pivoting movement may be
smaller or larger than 90.degree..
[0081] Although the wave spring 29 or 63 is employed as the holding
member in the foregoing embodiments, another structure may be
employed to hold the position of the operating knob 25 or 54. For
example, an engagement protrusion may be provided on an inner wall
surface of the cutout groove 26 or 60, and an engagement hole may
be provided in the flat plate-shaped portion 24 or 53. The position
of the operating knob 25 or 54 may be held by engagement of the
engagement protrusion and the engagement hole. A handicraft
embroidery frame may be used instead of the embroidery frame 10 or
30 which is attached to the sewing machine 1.
[0082] The foregoing description and drawings are merely
illustrative of the present disclosure and are not to be construed
in a limiting sense. Various changes and modifications will become
apparent to those of ordinary skill in the art. All such changes
and modifications are seen to fall within the scope of the appended
claims.
* * * * *