US998845A - Presser-foot-lifting mechanism for sewing-machines. - Google Patents

Description

J. HEGGIE. PRESSEK FOOT LIPTING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED MB. 9 1909.

998,845, v Patented July 25, 1911.

COLUMBIA PLANOGRAPH (10.. wAsHINumN. D. c.

Uhllt El) S JAMES I-IEGGIE, OF CLYDEBANK, SCOTLAND, ASSIGNOR TO THE SINGERJVIANUFAC- TUBING COMPANY, OF ELIZABETH, NE'l/V JERSEY.

PRESSER-FOOT-LIFTING MECHANISM FOR SEWING-MACHINES.

Specification of Letters Patent.

Patented July 25, 1911.

Application filed February 9, 1909. Serial No. 476,956.

To all whom it may concern:

Be it known that I, Juries l-lnoern, a subject of the King of the United Kingdom of Great Britain and Ireland, and residing at Clydebank, Dumbartonshire, Scotland, have invented a certain new and useful Improvement in Presser-Foot-Lifting Mechanism for Sowing-Machines, of which the following is a specification.

This invention relates to sewing machines for use in stitching leather, saddlery and like goods of uneven thickness, in which the feeding of the work is effected by a feed dog below acting in conjunction with a vibrating or feeding presser above the work: and it has for its object to provide a simplified and improved arrangement or combination of mechanism for so actuating the presser that it automatically climbs the stopped or uneven surface of the work as the thickness of the latter increases and in like manner descends as the thickness decreases, while the extent of lift over the goods remains practically uniform throughout and undue pressure or thud on the de scent of the presser is avoided.

In the accompanying drawings Figure 1 is a front view of the head of a sewing machine embodying the invention, the face plate being removed, Fig. 2 is a part plan thereof, and Fig. 3 is a part vertical section on the line 33, Fig. 2.

Referring to the drawings, the lifting movements of the presser are effected by a cam A formed on or fitted to the usual crank disk 0 on the forward end of the needle bar actuating shaft B. The needle-bar Z), carrying the needle 11, derives its usual reciprocatory movements from the actuating shaft B through the pitman (Z connected with the screw-stud 0 carried by the crankdisk 4. The said cam is tracked by roller 0 carried by a forked portion 0 at the lower end of a vertical plunger G fitted in the machine head D adjacent the face plate, (not shown). The plunger is slotted at its upper end 0 and the slot is entered by the end of a short clamping lever E pivoted at E on a jawed sleeve G fitted loosely on the upper end of the presser bar H so that the latter may freely slide within the sleeve G which is held in position by a screw threaded stud h entering the end of the presser bar, a washer I and spring J being interposed.

Between the aws of the sleeve G is a clamp ing member or collar K through which the presser bar passes freely when no pressure is applied to the clamping collar but which presser bar is rigidly held by the collar K when the end of the pivoted clamping lever E or, as shown, the point of an adjust;- able set pin or contact screw L carried thereby, is brought to bear on the side of the collar K so as to cause it to engage the presser bar H. As shown :in the drawings, the sleeve G is forked to form the two spaced jaws which are perforated to fit the presserbar If and the clan'iping member or collar K is also perforated to loosely fit the pres -1er-bar upon which it is locked between and by means of the spaced aws of the collar G in the desired relation to the other members of the lifting mechanism. As the collar K embraces the presser bar H and engages such part of its length as is within it for the time being, the cam A imparts a lift of uniform extent to the presser from its position of rest on the surface of the work irrespective of the thickness of the latter, while on the descent of the plunger C when cleared by the cam A the presser bar H is released from the collar so that the presser drops to rest on the work. Thus, while the presser climbs upward on to a stepped surface or downward therefrom, the lift remains normal and the thud due to excessive lift and drop of the presser is avoided.

Having now described my invention what I claim and desire to secure by Letters Patent of the United States is 1. In a sewing machine, the combination with the needle-bar actuating shaft, a reciprocating needle-bar, an operative connection between the forward end of said shaft and the needlebar, and a presser-bar, of a sleeve forked and perforated to form two spaced jaws fitted upon and embracing said presser-bar, a clamping member perforated to fit said presserbar and locked thereon be tween the jaws of said sleeve, a lever piv oted to said sleeve, a reciprocating plunger adapted on its movement in one direction to move said lever on its pivot and thereby bring the clamping member into clamping engagement with the presser-bar, and a cam on the needle-bar actuating shaft adjacent the connection with the needle-bar for opcrating the plunger.

2. In a sewing machine, the combination with the needle-bar actuating shaft, a reciprocating needle-bar an operative connection between said shaft and the needle-bar, and a presser-bar of a jawed sleeve embracing said presser-bar, a clamping collar loosely fitted upon the presser-bar and locked between the jaws of said sleeve, a lever pivoted to said sleeve and provided with a contact pin whose point is adjustable toward and from said collar, a reciprocating plunger mounted for movement parallel with the presser-bar and adapted on its movement in one direction to move said le ver on its pivot and thereby bring said collar into engagement with the presserbar, and a cam on the needle-bar actuating shaft adjacent the connection with the needle-bar for operating the plunger.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JAMES HEGG-IE.

Vitnesses VVALLAGE CRANSTON F AIRWEATHER, lVALLAoE FAIRVEATHER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

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