Sewing – Elements – Presser devices
Patent
1985-11-19
1987-11-17
Hunter, H. Hampton
Sewing
Elements
Presser devices
D05B 2900
Patent
active
047065877
DESCRIPTION:
BRIEF SUMMARY
FIELD OF ART
This invention relates to a presser foot lifter in a sewing machine and more particularly, to a presser foot lifter in a sewing machine which is capable of lifting the presser foot adapted to hold a workpiece or workpieces such as a piece or pieces of cloth to be sewn against the throat plate at any desired height with a small force.
BACKGROUND OF THE INVENTION
Hithertofore, in conventional presser foot lifters in sewing machines of the type referred to hereinabove, as shown in FIG. 1, the presser foot 3 is held against the throat plate 2 by means of the presser bar spring 1 comprising a compression spring and is lifted to a predetermined height against the force of the presser bar spring when the solenoid 4 is excited. That is, in the lifter of FIG. 1, when the knee-operated switch 6 embedded in the knee abutment member 5 is switched on by the operator's knee, the solenoid 4 is excited to rotate the knee-operated lifting lever 7 in the counterclockwise or arrowed direction which in turn lifts the presser rod 9 which is slidable within the oil sump 8. As the lifter rod 9 is lifted, the bar 10 is lifted to rotate the lever 11 in the clockwise or arrowed direction which in turn moves the connector rod 12 rightwards or in the arrowed direction to rotate the lever 13 in the clockwise direction. As the lever 13 rotates in the clockwise direction, the lever abuts against and upwardly pushes the stop rod 15 secured to the presser bar 14 having the presser foot 3 secured to the lower end thereof. Thus, as the stop rod 15 is pushed upwardly, the presser bar 14 is lifted against the force of the presser bar spring 1 whereby the presser foot 3 is lifted away from the throat plate 2.
However, in the above-mentioned conventional presser foot lifter, since the presser foot is designed to be lifted by the excitation of the solenoid, although the operator can lift the presser foot with a small force, the conventional presser foot lifter has the disadvantage that the presser foot 3 is allowed to move between only two positions, that is, the lowermost position in which the presser foot 3 contacts the throat plate 2 and the uppermost position far above the throat plate, and cannot be lifted to a position above the throat plate by a small distance or a position convenient for the operator to operate the lifter.
DISCLOSURE OF THE INVENTION
The present invention has as its object the provision of a presser foot lifter for a sewing machine which can eliminate the disadvantages inherent in the conventional sewing machine presser foot lifter referred to hereinabove. That is, the present invention intends to enable the presser foot to be lifted to any desired position above the throat plate with a small force.
In order to attain this object, the presser foot lifter for a sewing machine includes a pressure relief mechanism adapted to lessen the force of a spring means which normally biases the presser foot towards the throat plate, a presser foot driving mechanism for lifting the presser foot and an operation mechanism operable by the operator. Upon the actuation of the operation mechanism, the pressure relief mechanism is operated to lessen the force of the spring means which urges the presser foot against the throat plate and, after the force of the spring means has thus been lessened, the presser foot driving mechanism is operated by the operation mechanism to drive the presser foot to a desired position above the throat plate.
By virtue of the presser foot lifter of the present invention, since the presser foot can be lifted with a small force, fatigue on the part of the operator can be substantially lessened. And according to the present invention, since the presser foot can be lifted to any desired position above the throat plate, the lifter can be applied to workpieces of various thicknesses to thereby substantially enhance the operating efficiency of the sewing machine.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view in partial section of a conventional sewing machine presser foot lifte
REFERENCES:
patent: 3353511 (1967-11-01), Marino
patent: 3601072 (1971-08-01), Husted
patent: 4246856 (1981-01-01), Sansone et al.
patent: 4388886 (1983-06-01), Adams
Hunter H. Hampton
Tokyo Juki Industrial Co. Ltd.
LandOfFree
Presser foot lifter in sewing machine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Presser foot lifter in sewing machine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Presser foot lifter in sewing machine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1442690