US708940A - Presser-foot-lifting mechanism for sewing-machines. - Google Patents

Description

N0. 708,940. Ptented Sept. 9, I902.

C. TI'IEUBALD.

PBESSEB FOOT LIFTING MECHANISM FOR SEWING MACHINES.

(Application filed Am. 28, 1902.)

(N0 Model.)

2 Sheets-Sheet l.

62/272962? 77e0Za/qi wihieape o v Patented Sept. 9, I902; C. THEUBALD. PRESSER FO'OT LIFTING MECHANISM FOR SEWING MACHINES. I (Application filed Apr. 28, 1902.i (No'ModeL) 2Sheets-Sheet 2.

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NrrED STATES "tries.

ATENT CONRAD THEOBALD, OF BRUNING, NEBRASKA.

SPECIFICATION forming part of Letters Patent No. 708,940, dated September 9, 1902.

Application filed April 28, 1902. Serial No. 105,081. (No model.)

To all whom it may concern:

Be it known that I, CONRAD THEOBALD, a citizen of the United States, residing at Bruning, in the county of 'lhayer and State of Nebraska, have invented new and useful Improvements in Sewing-Machines, of which the following is a specification.

My invention relates to improvements in sewing-machines, and particularly relates to lifters for presser-bars and means for holding the bar elevated and combined therewith mechanism for adjusting or operating the tension device; and the objects are to provide improved mechanism for lifting and holding the presser-bar in raised position by a system of levers arranged to be actuated by the pressure of the knee or leg of the operator, and at the same time by the same mechanism release and apply the tension of the thread as fed from the spool, and also to provide improved means for engaging the presser-foot bar and hold it in elevated position.

With these objects in View my invention consists in the novel construction of parts and their arrangement and aggroupment in Operative combination, as will be hereinafter fully described and the novelty thereof particularly pointed out and distinctly claimed.

I have fully and clearly illustrated the improvements in the accompanying drawings, wherein- Figure 1 is a perspective view of a sewingmachine having my improvements connected thereto, the table being broken away to show the parts of the mechanism located thereun-- der. Fig. 2 is a side elevation of the armof the sewing-machine, partly in vertical section, to show the mechanism assembled within the head of the arm. Fig. 3 is a top plan View of the head and portion of the arm, partly in horizontal section, and showing the ratchet-pinion and actuating-pawl arm of the pitman to operate the ratchet. Fig. 4 is a detail front view of the head, showing the presser-bar and attached rack plate or bar. Fig. 5 is a detail perspective of the rack-bar as removed from its connectionsto the presserbar. Fig... 6 is a detail perspective of the bell-crank lever, showing the teeth to engage the rack-bar of the resser-bar. Fig. 7 is a detail perspective of the ratchet-pinion and trip-wheel for holding the presser-bar in raised position. Fig. 8 is a detail perspective of the lever which engages the tension devices. Fig. 9 is a detail View of the coupling, the parts being shown as separated. Fig. 10 is a perspective view of the tension device, showing the parts as closed. Fig. 11 is a perspective view of the tension device, showing the upper plate as raised to relieve the tension on the thread.

Referring to the drawings, A designates the standard, and B the overhanging arms, of the sewing-machine, which may be of any of the well-known constructions, and O designates the base-plate, on which the standard is secured or forms an integral part.

It is not deemed essential to describe or show the various actuating mechanism common to all machines to operate the needle, since these are well known, and my invention forms no part thereof, being intimately associated with the presser-bar and tension devices.

D designates the head, formed on the free end of the arm and chambered out to receive the eccentric (not shown) which actuates the needle-bar 1 in the usual well-known manner. To the face of the head is secured by any Well-known means the plate 2,. which closes in the mechanism. The common form of presser-bar 3 is carried by the plate 2, being arranged in a half-circle vertical groove 4: and slidingly projected through a guidebracket 5 and through the flange 6 at the lower end of the plate 1, as shown in the drawings, and on the presser-bar is arranged the usual expansive spring 7 to return and hold the bar to its lower position when the restraint on the spring is removed. My improvements do not interfere with the usual means for lifting and holding the presser-bar in raised position, which means consists of a pin 8, projected from the bar through a slot in the plate, and a cam disk or plate 9, pivotally supported on the plate 2 and bearing against the pin 8. My improvements are more particularly utilized when the operator is engaged in doing work where it is necessary or more convenient to use both hands in its manipulation. It does not, however, in-

terfere with the use of the lifting and holding means above described.

Now describing my improvements as illustrated in the drawings, 10 designates a lever pivotally mounted under the table, as at 11, and at its free end has jointed to it a legpiece 11, having a vertically-depending arm against which the knee or leg of the operator may engage to operate the lever, the hinged connection of the sections or parts of the lever being such that the leg-section turns only to alinement with the lever, as indicated, and so that when not in use it may be swung around under the table and lie against the lever. The lever 10 is slidingly supported on a rigid rod 12, and between the lever and the wall of the table on the rod 12 is placed an expansive spring 13, by the force of which when the lever is moved to compress the spring it is returned to initial position on release of the compressing force. At about midway the length of the lever 10 is pivotally connected one end of a rod 14, loosely projected through a hanger 15, depending from the table. The other and free end of the rod 14 is formed with a hooked coupling-head 15, which detachably engages with a counterpart coupling 16 on the end of a rod 17, loosely supported in a hanger 18, depending from the bottom side or" the base of the sewing-machine, the other and outerend of the rod 17 being pivotally connected to the lower end of a rocking lever or rod 19, pivotally supported by a pin 20, fixed in the standard A. To the upper end of the rock-lever is pivotally secured a horizontally-arranged pitman 21, to the forward end portion of which, adjacent to the headpiece, is pivotally hung a link or bar 22, constituting a lever, the lower end of which is pivotally arranged on a pin 23, fixed in a block or support 24. To the inner projecting end of the pin 23 is mounted, to rock thereon, a bell-crank lever 25, having formed on the end of its lower and forwardly-projecting arm a determined number of teeth 26, which engage with a rack carried by the presser-bar. The vertical arm of the bellcrank lever is provided with a laterally-projecting pin 27, which engages in a notch or recess 28 in the lever 22, so that when the lever-is drawn back by the pitman 21 the recess engages the pin and rocks the bell-crank lever. Tothepresser-barissecured orformed integral therewith a plate 29, formed with a recess 30 to set over the bracket 5 on the head-plate to permit the raising and lowering of the presser-bar, and on the inner edge of the plate 29 is formed a rack 31, which is engaged by the teeth on the end of the bellcrank lever. The plate 29 is also formed with an elongated recess 32 to afford room for the engagement of the trip wheel or spider to hold the presser-bar in elevated position. In the inner wall of the head is formed a chamber or housing 33, wherein isjournaled a vertical shaft or arbor 34, on which is mounted a ratchetpinion 35, having a determined number of ratchet teeth thereon, usually eight, and above the ratchet-pinion on the shaft 34 is fixed a trip-spider 36, having four diametrically-disposed arms arranged to project beyond the perimeter of the ratchet-pin ion and into the recess 32 of the plate 29, carried by the presser-bar, so that when the bar is lifted and an arm of the spider is turned to engage in the recess the arm will rest under the upper wall of the recess 32 and hold the presser-bar from further descent until the arm of the spider is moved from under the end of the recess, when the presser-bar drops under the force of the spring. To actuate the ratchet-pinion and spider, the pitman 21 is extended beyond the connection to the link 22, as at 37, the extension being arranged in a sleeve or way 38, which opens into the chamber 33, wherein the ratchet-pinion and spider are contained, and on the end of the extension is provided or formed a pawl-catch 39, which moves in the path of the ratchets and by its engagement therewith turns the pinion to carry the spider-arms into the recess of the plate on the presser-bar and under the end thereof to hold the presser-bar lifted and at the next movement turns the spider-arm from its engagement and so that the plate of the presser-bar stands free between two arms of the spider.

It will be perceived from the foregoing description and reference to the drawings in connection therewith that the operation of the described mechanism may be stated as follows: The hinged leg-piece is first turned in alinement with the main bar of lever 10, so as to be accessible to the knee or leg of the operator, and the coupling having been hooked up the mechanism is ready for being utilized. Then by pressing the lever 10 toward the adjacent end of the table the bars 14 17 are moved in the same direction, rocking the lever 19 to move its upper end outward, which pulls the pitman in same direction, and with the pitman moves the lever 22 into contact with the pin 27 in the bell-crank lever and raising the lower arm of that lever, which, being in engagement with the rack, raises the presser-bar, and when the upper end of the recess 32 has passed the spider the pawl-catch on the extension of the pitman engages the ratchet-pinion and turns it so as to bring an arm of the spider into the recess in the plate of the presser-bar when the pressure on the lever is removed, and the force of the spring 13 throws the lever, with the pitman, in opposite direction and the presserbar is free to move down and lodge on the arm of the spider in its path. Of course the presser-foot is raised by these movements from off the work, and the operator has both hands free to adjust the work as may be desired or required. When it is necessary to release the presser-bar, the mechanism is again brought into requisition and the presser bar lifted or raised off its contact with the arm of the spider, which is then turned by the pawl catch and ratchet from under the end of the recess and until the plate on the presser-foot will stand in the angle between two of the arms of the spider and the presserhat-free to descend, when the pressure on the leg-piece can be removed and the mechanism disengaged, in which position the connection between the teeth of the bell-crank lever and the rack on the presser-bar imposes no interference with the free movement of the bar.

I also provide a tension device operated by the mechanism which lifts the presser-bar and which relieves the tension on the thread simultaneously with the operation of the raising of the presser-bar and restores the tension when the presser-bar is lowered to resume sewing. This tension device is shown in Figs. 1 and 2 in connection with the pitman and illustrated with particularity in Figs. 10 and 11, and reference being thereto had it will be disclosed that on vertical studs formed on the upper side of the arm 13 is arranged a flat metal plate 40, formed with a recess or indentation 41 to afford space for manipulating the thread and its insertionin the tension. cured a coincident spring-plate 42, secured by a screw 43, let through both plates and projecting into one of the studs, substantially as shown. In the plate 42 is a thread-slit 44, leading into a thread hole or eye 45, and the end of this plate is formed with a hollow angular sleeve 46. The thread is yieldingly held between the surfaces of the plates under the spring portion and is fed up through the eye 45 to the usual eyes on the head of the arms to the needle. To the side of the overhanging arm B is secured a standard 47, provided with a bearing wherein is journaled a rod 48, having a vertically-depending arm 49, which loosely engages in a slot formed in aplate 50, secured to the pitman 21. On the free end of the rod 48 is aplate5l,which is arranged within the angular sleeve 46 and is adapted to turn or rock with the rod 48 and lift the upper spring-tension plate, so as to have the thread free to be pulled forward when required. It will be perceived that when the pitman is drawn back to lift the presser-bar the arm 49 will engage the frontend of the slot in plate 50 on the pitman, and be moved therewith, and eventuate in turning the plate 51 and lift the spring-tension plate, thereby releasing the tension on the thread and permit it to be drawn forward. WVhen the pitman moves forward, the arm 49 is free again and the spring-tension plate automatically closes down on the lower plate and renews the tension of the thread.

On the plate 40 is laid and se- Having thus described the invention, what is claimed as new is 1. A mechanism for lifting the presser-bar of a sewing-machine, comprising a presserbar formed with rack-teeth, a bell-crank lever having teeth on the end of one arm to engage the said rack, a pivotally-supported lever to engage the other arm of the bell-crank lever, a reciprocable pitman to operate the lever, and means to reciprocate the pitman.

2. In a mechanism for lifting the presserbar of a sewing-machine, the combination of a presser-bar formed with rack-teeth, a bellcrank lever having teeth on one arm to engage the said rack-teeth and provided with a pin in its upper end, a pivotally-supported lever 22 to engage the pin in the free arm of the bell-crank lever, a reciprocable pitman to which the upper end of the lever 22 is connected, a rocking lever to operate the pitman, and a lever under the table of the machine to rock the rocking lever.

3. In a mechanism for lifting the presserbar of a sewing-maohine, the combination with a reciprocable pitman having a pawlcatch on its inner end and means connected thereto for lifting the presser-bar, ofa vertical shaft, a spider-wheel mounted on the shaft, a ratchet-pinion mounted on said shaft in. the

path of the pawl-catch, and means to actuate the pitman to engage the pawl-catch with the ratchet-pinion and turn the spider-wheel to engage and hold the presser-bar elevated.

4. In a mechanism for lifting the presserbar of a sewing-machine, the combination of thelit'ting mechanism,thepresser-barformed with a recess, a ratchet pinion, a spiderwheel turned thereby, and means to turn the ratchet pinion with the spider-Wheel whereby an arm of the spider is carried within the recess to support the presser-bar in raised position.

5. In a mechanism for raising and supporting the presser-bar of a sewing-machine, the combination of the presser-bar, a rotatable ratchet-pinion, a spider-wheel rotated thereby, means to lift the presser-bar, a pitman to actuate the lifting mechanism and to rotate the ratchet-pinion and bring the spider into engagement with the presser-bar, and a lever to operate the pitman.

In testimony whereof I affix my signature in presence of two witnesses.

CONRAD TI-IEOBALD.

WVitnesses:

FRANK BRUNING, W. H. GRENE.

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