U.S. patent number 3,796,173 [Application Number 05/202,892] was granted by the patent office on 1974-03-12 for presser mechanism for sewing machines.
This patent grant is currently assigned to Union Special Machine Company. Invention is credited to Ronald A. Godsen.
United States Patent |
3,796,173 |
Godsen |
March 12, 1974 |
PRESSER MECHANISM FOR SEWING MACHINES
Abstract
This disclosure relates to a low inertia adjustable stroke
presser foot for sewing machines which is operable to feed the
uppermost ply of superimposed plies being sewn to compensate for
the drag exerted by the presser foot sole upon the upper ply. The
presser foot is automatically driven through its cooperation with
the feed dog and effects the feeding of the upper ply at the
termination of the work feeding action of the feed dog. The presser
foot includes two sole plates mounted for operation in unison while
being relatively movable to one another to compensate for a
variation in the number of plies between the two sole plates.
Inventors: |
Godsen; Ronald A. (Chicago,
IL) |
Assignee: |
Union Special Machine Company
(Chicago, IL)
|
Family
ID: |
22751654 |
Appl.
No.: |
05/202,892 |
Filed: |
November 29, 1971 |
Current U.S.
Class: |
112/235 |
Current CPC
Class: |
D05B
29/00 (20130101) |
Current International
Class: |
D05B
29/00 (20060101); D05b 029/00 () |
Field of
Search: |
;112/235,237,238,239,240,150,151,134 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Boler; James R.
Assistant Examiner: Nerbun; Peter
Attorney, Agent or Firm: Brown; Charles E.
Claims
I claim:
1. A presser foot assembly for a sewing machine, said presser foot
assembly comprising a support arm terminating in a bifurcated end
portion, a pivot pin carried by said end portion, a first sole
plate carried by said pivot pin for pivotal movement only relative
to said end portion, a second sole plate carried by said pivot pin
for pivotal movement and limited movement generally normal to the
general plane of said second sole plate, and cooperating means on
said first and second sole plates restricting relative movement
between said first and second sole plates, said cooperating means
including said first sole plate having an upper ledge overlying
said second sole plate, and resilient means between said ledge and
second sole plate constantly urging said second sole plate towards
a work engaging position.
2. The presser foot assembly of claim 1 wherein said resilient
means include springs disposed on opposite sides of said pivot
pin.
3. The presser foot assembly of claim 1 together with a lower ledge
on said first sole plate cooperating with said second sole plate
limiting downward movement of said second sole plate in response to
urging of said resilient means.
4. The presser foot assembly of claim 1 wherein said cooperating
means include coacting portions of said first and second sole
plates in alignment with said pivot pin substantially filling the
space within said bifurcated end portion along said pivot pin
thereby assuring positioning of said first and second sole plates
axially of said pivot pin.
Description
This invention relates in general to new and useful improvements in
sewing machines, and more particularly to an improved presser foot
assembly for sewing machines of the type in which a presser foot is
disposed on one side of the work and is biased in opposition to a
movable work feeding member disposed on the opposite side of the
work. The invention particularly relates to a presser foot assembly
of this type wherein different numbers of work plies underlie
different portions of the presser foot and separate sole plates are
provided for engaging the different plies.
BACKGROUND OF THE INVENTION
This invention particularly relates to a low inertia adjustable
stroke presser foot for sewing machines of the type disclosed in
the copending application of Edgar Schoij and Frederick M. Klose
entitled PRESSER MECHANISM FOR SEWING MACHINES, Ser. No. 878,635
filed Nov. 21, 1969, now U.S. Pat. No. 3,623,441.
The sole plates of the various presser foot arrangements disclosed
in the aforementioned copending application Ser. No. 878,635 is a
planar sole plate intended primarily for the sewing of plies which
extend entirely beneath the presser foot. However, there are many
sewing operations wherein one portion of the presser foot overlies
only one ply of work, for example, and a second portion of the
presser foot overlies a multiple number of plies of work. This is
particularly true in such operations as sewing on pockets, collars,
cuffs, etc. The situation also exists in such hemming operations as
shirt sleeves, blouses, skirts.
In the past, there have been developed compensating presser feet of
the type wherein two sole plates are provided, the sole plates
being relatively movable with respect to one another whereby one
sole plate may engage only a single work ply and the other sole
plate will engage one or more work plies which are being stitched
to the one work ply. Typical of these compensating presser foot
constructions are those found in the patents to John T. Enos
entitled SEWING MACHINE PRESSER-FOOT, U.S. Pat. No. 2,652,016,
granted September 15, 1953, and James A. Pisano entitled CORDING
PRESSER-FOOT FOR SEWING MACHINES, U.S. Pat. No. 2,807,225, granted
Sept. 24, 1957. While the individual sole plates of these prior
presser foot constructions are mounted on common pivots carried by
a bracket, the constructions in no way co-ordinate the pivoting of
the two sole plates nor is such co-ordination necessary in that the
bracket is rigidly mounted on the presser bar and there is no
change in the angular relation of the bracket with respect to the
plane of the work being stitched.
SUMMARY OF THE INVENTION
In accordance with this invention, there is provided a low inertia
adjustable stroke presser foot for sewing machines which is also of
the compensating type and is provided with first and second sole
plates mounted both for movement in unison and for individual
movement relative to one another.
A principal feature of the invention is the provision of a support
arm which is part of a lever pivotally mounted for cooperating
reaction with respect to a four motion feed assembly whereby a sole
plate or sole plates carried thereby may automatically feed the
upper work layer or layers to compensate for the resistance to
movement of the upper work ply with the lower work ply as it is
being fed by the feed mechanism. This support arm is provided with
first and second sole plates which are mounted on a pivot pin
carried by the support arm with the first and second sole plates
having cooperating means whereby the first and second sole plates
generally move in unison with respect to the support arm and at the
same time are relatively movable with respect to one another,
primarily in a vertical direction, to compensate for the varying
number of plies underlying the two sole plates.
A feature of the invention is the inter-relationship of the two
sole plates whereby the two sole plates react against one another
for relative movement and at the same time are generally movable
together as a unit for pivoting about the pivot pin mounting the
same.
With the above and other objects in view that will hereinafter
appear, the nature of the invention will be more clearly understood
by reference to the following detailed description, the appended
claims and the several views illustrated in the accompanying
drawings:
IN THE DRAWINGS
FIG. 1 is a partial left end elevational view of a lockstitch
machine with parts broken away and shown in section, and
incorporating the presser mechanism of this invention.
FIG. 2 is a front elevational view of the presser mechanism of FIG.
1 together with adjacent portions of the machine.
FIG. 3 is an enlarged rear elevational view of the presser
mechanism.
FIG. 4 is a vertical sectional view taken along the line 3--3 FIG.
4 and shows the specific details of the presser mechanism.
FIG. 5 is an enlarged fragmentary vertical sectional view taken
along the line 5--5 of FIG. 1.
FIG. 6 is a fragmentary vertical sectional view taken along the
line 6--6 of FIG. 4 and shows the relationship of work plies with
respect to the sole plates.
FIG. 7 is an exploded perspective view showing the double sole
plate construction of the presser mechanism.
Referring now to the drawings in detail, it will be seen that there
is illustrated in FIG. 1 a base 10 of a lockstitch machine with a
conventional feed mechanism, generally identified by the numeral
11, including a feed dog 12. There is also illustrated the
customary rotary hook 13 and throat plate 14, all mounted on the
base 10.
Above the base 10 there is illustrated a portion of the
conventional head 15 which carries in the normal manner a presser
bar 16 and a needle bar 17 mounted for vertical reciprocal movement
in bushings 18,19, respectively, with a needle 20 being mounted in
the lower end of the needle bar 17. A presser foot, formed in
accordance with this invention and generally identified by the
numeral 21, is carried by the lower end of the presser bar 16 and
includes a bracket 22 which, as is best shown in FIG. 4, has a bore
23 receiving a reduced diameter portion 24 of the presser bar 16.
The bracket 22 carries suitable set screws 25 (FIG. 2) securing the
same on the presser bar 16.
As is best shown in FIGS. 3 and 4, the bracket 22 has a solid top
portion 26 and two downwardly spaced wall portions 27. A stud or
pivot pin 28 extends through and between the walls 25 with one end
portion 30 of the pivot pin 28 being threaded and being threaded
into a like threaded bore 31 in one of the wall portions 27. A
bellcrank type lever 32 having a centrally located bushing 33
receiving the pivot pin 28 is mounted for pivotal movement relative
to the bracket 22 with an upper portion of the lever 32 being
disposed between the walls 27.
With particular reference to FIG. 4, it will be seen that the lever
32 includes an upper arm 34 which extends horizontally to the left
between the walls 27 and terminates in a bifurcated portion 35. An
eyebolt 36 has the eye thereof mounted within the bifurcated
portion 35 for pivotal movement by means of a pin 37 carried by the
bifurcated portion 35 and extending transversely thereof. The bolt
36 extends upwardly and through an elongated slot 38 in the solid
portion 26 of the bracket 22 and threadedly engaged on the upper
end portion of the bolt 36 is a nut 40 having a generally conical
shoulder portion 41 depending therefrom.
A spring 42 is contained on the bolt 36 between the nut 40 and the
solid portion 26 of the bracket 22 by the nut 40. It will be
readily apparent that when the nut 40 is properly adjusted, the
spring 40 will be compressed and the bolt 36 tensioned so as to
urge the lever 32 to pivot about the pivot pin 28 in a clockwise
direction. A stop nut 43 is adjustably threaded on the bolt 36 and
is engageable with the bracket 22 to limit pivotal movement of the
lever 32 in a counterclockwise direction. The stop nut 43 is
retained in an adjusted position by means of a lock nut 44.
With particular reference to FIGS. 1 and 5, it will be seen that
the bracket 22 has formed in the solid upper portion 26 thereof
between the slot 38 and the presser bar 16 a threaded bore 45
opening entirely therethrough and having adjustably positioned
therein a stop screw 46 which is engageable with the upper surface
of the arm 34 of the lever 32. The stop screw 46 limits the pivotal
movement of the lever 32 in a clockwise direction.
The lever 32 also includes a second arm 47, which will be described
hereinafter as a support arm. The support arm 47 extends angularly
downwardly and to the right from the pivot pin 28 and terminates in
a bifurcated portion 48, as is best shown in FIGS. 6 and 7. The
bifurcated portion 48 includes a pair of spaced walls 50,51 having
mounted therein transversely aligned bearings 52,53, respectively.
The bifurcated portion 48 carries a transverse pivot pin 54 which
has end portions thereof seated within the bearings 52, 53 for
rotation relative to the bifurcated portion 48.
The pivot pin 54 carries two separately formed and separately
acting sole plates generally identified by the numerals 55 and
56.
The sole plate 55 includes a lower work engaging plate member 57
which has a mounting block 58 extending upwardly therefrom. The
mounting block 58 has a transverse bore 60 therethrough of a size
to receive the pivot pin 54. The pivot pin 54, in the final
assembly of the sole plates 55,56, with the bifurcated portion 48,
is locked in a center position to the mounting block 58 by means of
a set screw 61. Thus, the sole plate 55 is mounted for pivotal
movement only with respect to the bifurcated portion 48, the pivot
pin 54 rotating within the bearings 52,53.
It is also to be noted that the upper portion of the mounting block
58 is contoured to provide suitable clearance for the upper part of
the bifurcated portion 48. Furthermore, the block 58 is offset
outwardly from the inner edge of the plate member 57 to define a
lower ledge 62. In addition, the upper part of the block 58
projects inwardly over and beyond the lower ledge 62 to define an
overhanging upper ledge 63. The ledges 62 and 63 cooperate with the
sole plate 56 in a manner to be described hereinafter.
The sole plate 56 also includes a lower work engaging plate member
64 which has a mounting block 65 extending upwardly therefrom. The
mounting block 65 has formed therein a transverse groove 66 of a
width corresponding to the diameter of the pivot pin 54. Thus, the
sole plate 56 is mounted for both rocking and vertical sliding
movement relative to the bifurcated portion 48.
On opposite sides of the groove 66, the mounting block 65 is
provided with a pair of bores 67 (FIG. 4) in which are seated lower
ends of springs 68. It is also to be noted that the lower part of
the mounting block 65 is generally aligned with the inner edge of
the plate member 64 and that the upper part of the block 65
overhangs inwardly beyond the inner edge of the plate member 64 to
define an abutment 70.
When it is desired to assemble the plate members 55,56 with the
support arm 47, the springs 68 are engaged beneath the ledge 63 and
then compressed, after which the sole plates 55,56 are slid
together so that the inner surfaces of the blocks 58,65 abut one
another. At this time downward movement of the sole plate 56
relative to the sole plate 55 due to the urging of the springs 68
is limited by engagement of the abutment 70 with the lower ledge
62. The sole plates 55,56, so coupled, are then positioned between
the walls 50, 51 of the bifurcated portion 48 and the pivot pin 54
is passed through the bearing 52, the bore 60, the groove 66 and
the bearing 53. With the pivot pin 54 centered, the set screw 61 is
tightened to lock the assembly together.
It will be readily apparent that the sole plates 55, 56 are mounted
for pivoting in unison about the pivot pin 54 while at the same
time the sole plate 56 is movable relative to the sole plate 55
both vertically and through a limited rocking movement.
Referring to FIG. 4, it will be seen that a spring, generally
identified by the numeral 71, is carried by the lever 32 and reacts
on the rear portion of the plate member 57 urging the same to pivot
in a counterclockwise direction (FIG. 4) about the pivot pin 54 and
to retain a normal horizontal position. The spring 71 has an upper
end portion 72 which is secured to the underside of the arm 34 by a
screw 73 threaded thereinto. The spring 71 also has a generally
S-shaped central portion 74 and a lower portion 75 which lower
portion 75 engages the plate member 57 and serves to keep the sole
plates 55,56 in a selected angular relation relative to the support
arm 47, more particularly in a horizontal position when the presser
mechanism is lifted for insertion or removal of a workpiece.
Referring now to FIG. 6, it will be seen that there is illustrated
a practical application of the presser foot 22 in applying a shirt
pocket 76 to a shirt 77. The edge of the shirt pocket has an
inwardly directed fold 78. Thus, the sole plate 55 overlies three
layers of work while the sole plate 56 overlies only a single layer
of work. When the presser bar 16 is moved downwardly to apply the
presser foot 22 to the work, the sole plate 55 would apply the
desired pressure to the three plies of work with the support arm 47
being disposed at the desired angle through the compression of the
spring 42 so as to affect the necessary additional feeding of the
material of the pocket 76 relative to the base material of the
shirt 77. At the same, time, the sole plate 56 would offset
downwardly relative to the sole plate 55 under the influence of the
spring 68 and serve as an edge guide for the pocket 76 and also to
prevent flagging of the material.
It is to be understood that the amount of pressure applied to the
material being stitched by the main sole plate 55 will depend upon
the compression of the spring 42 in that this is adjustable by
positioning the nut 40. The amount of pressure applied to the
material will depend on the type of finish of the material or the
thickness of the material. For example, more pressure would be
required for smooth or thin material than for rough or thick
material in order to obtain a flat, pucker-free seam.
It is once again pointed out here that without consideration being
given to the sole plate 56, the sole plate 55 will function in the
manner described in the afore-mentioned copending application Ser.
No. 878,635 while the sole plate 56 will have no feeding
function.
Although only a preferred embodiment of the presser foot mechanism
has been specifically illustrated and described herein, it is to be
understood that minor variations may be made in the presser foot
construction without departing from the spirit and scope of the
invention, as defined by the appended claims.
* * * * *