US2919668A

US2919668A - Articulated presser foot for sewing machines

Info

Publication number: US2919668A
Application number: US691614A
Authority: US
Inventors: Adam Hermann; Neumann Friedrich
Original assignee: PHOENIX NAHMASCHINEN A G BAER
Current assignee: PHOENIX NAHMASCHINEN A G BAER; Phoenix Nahmaschinen A-G Baer & Rempel
Priority date: 1956-10-23
Filing date: 1957-10-22
Publication date: 1960-01-05
Anticipated expiration: 1977-01-05
Also published as: GB827565A; CH361968A

Description

Jan. 5, 1960 H. ADAM ETAL 2,919,668

ARTICULATED PRESSER FOOT FOR SEWING MACHINES Filed Oct. 22. 1957 M a ZGf/Vf United States Patent ARTICULATED PRESSER FOOT FOR SEWING MACHINES Hermann Adam and Friedrich Neumann, Bielefeld, Germany, assignors to Phoenix Niihmaschinen A.-G. Baer 8: Rempel, Bielefelti, Germany Application October 22, 1957, Serial No. 691,614

Claims priority, application Germany October 23, 1956 4 Claims. (Cl. 112235) Sewing machines are known having a presser foot which is either made of one piece or which has a sole which is pivotally connected by means of a pin to the shank portion of the foot. The rigidly constructed press er foot or the foot having the sole with a pivot joint is secured by means of a screw to the lower end of the presser bar of the sewing machine.

Differently constructed presser feet are required for the performance of various types of sewing operations. In connection with presser feet in which the shank of the foot and the sole are inseparably connected with each other, it is necessary to exchange the entire presser foot when changing over from one type of sewing operation to another.

It is an object of the present invention to provide an articulated presser foot having a sole which can be releasably and pivotally connected to the shank of the foot by means of suitable mechanism.

It is a further object of the invention to provide a presser foot having a releasable connection between the sole of the foot and the shank whereby the sole can be conveniently exchanged for a sole of different construction, thus making it unnecessary to release the upper foot portion or shank from the presser bar.

It is still a further object of the invention to permit continuous use of the presser foot shank by providing for releasable connection of difierent foot soles and thus aiford a saving in costs.

It is a still further object of the invention to provide for the connection of the foot sole to the shank portion in such a manner that the exchange of the different soles can be effected in a simpler manner than heretofore the exchange of the entire presser foot.

In accordance with a still further object of the invention the guiding of the material on the base plate of the machine must not be impeded in any manner in spite of such manner of linking the foot sole while the sole is maintained in secured position on the shank without inadmissible tolerance and also without jamming effect on the shank.

Accordingly, the invention provides first of all for an adjustable catch lever which is adjustable by means of an operating member which for the locked position encompasses the pivot pin provided in the sole of the foot with a throat portion. A finger lever pivotally mounted in the shank portion of the foot and to which is linked a portion of the catch lever serves as the operating or manipulating member. In the locked position of the device the hook shaped throat of this catch member or lever operatively engages the mouth of the shank member by encompassing the joint or connecting pin of the foot sole member. This operating device can be formed as a self locking knee joint or toggle joint. Moreover, this operating device can be constructed in such a space conserving manner that no member needs to project laterally of the shank portion. Thus the presser foot retains its Patented Jan. 5, v1960 ice entirely smooth lateral walls and thus does not impede the guiding of the material in any manner.

Interchangeable foot soles are known per se in connection with attachment devices which serve the purpose of adapting a straight sewing machine as a zig-zag sewing machine. In this connection, however, the articulated linking of the foot sole with the attachment device is so cumbersome that the exchanging of the feet can hardly be expected of a housewife. Moreover, the linking of the foot is undertaken in such a manner that faultless guiding of the material is not possible.

Furthermore, in such atachment devices there are interchangeable presser feet which are only linked on under the pressure of springs. In that event sufficiently satisfactory seating of the foot sole without danger of lateral tilting is not insured.

Further objects and advantages of the invention will become apparent from the following specification with reference to the drawings which show one embodiment of the subject of the invention and in which- Fig. 1 is a front perspective view of the presser foot shank with supporting means for the presser foot sole in opened condition,

Fig. 2 is a side elevational view showing the presser foot sole pivotally mounted on the shank,

Fig. 3 is a perspective view of the presser foot sole with connecting pin for the supporting means taken from the side and top,

Fig. 4 is a sectional view taken along line IVIV in Fig. 2, and

Fig. 5 is a sectional view drawn to a largerscale and taken along line VV in Fig. l.

in the rear portion of the shank 1 of the foot an apertured lug 2 is provided which is slotted and in which the finger or manipulating lever 4 is retained by means of a connecting pin 3 which is tightly mounted in the aperture of the right hand portion of the lug in which it is rotatable by means of a screw driver during initial adjustment. The finger lever 4 can be pivotally moved on this support or journalling arrangement. The catch member 6 is pivotally connected by means of a pin 5 to the finger lever 4 and is hook shaped at its forward end which reaches with its throat 7 through the slot 8 of the shank portion 1 for the purpose of encompassing the joint pin 9 which is supported .between the upstanding flange portions 10a of the foot sole 10.

The shank portion 1 likewise presents a throat or mouth 11 at its forward end to receive the joint pin 9. When placing the foot sole 10 into the shank portion the sole is placed into the opened mouth portion 11 by means of the joint pin 9. Coupling link 6 rests with its right hand end on pin 9. Thereupon the finger lever 4 is flung upwardly. Fig. 2 indicates how lever 6 with pin 5 is pulled to the left and upwardly around pivot pin 3, slightly above dead center position. As a result the throat 7 firmly places itself around the joint pin 9 ahead of throat l1 and securely holds the sole 10. The pin 3, the pin 5 and the abutment formed by the throat 11 are arranged in such a relationship to one another that the locking position of the finger lever 4 provides a toggle joint effect. The pin 3 for this purpose is provided with an offset or eccentric portion which can be moved in order to make it possible that in initially adjusting the device for the tightened position of the toggle joint the support of the joint pin 9 of the foot sole 10 is insured without excessive tolerance but also without the possibility of a jamming eliect.

The mounting of the shank 1 onto the material presser bar 13 may be accomplished in the usual manner by means of the shank screw 12. However, it is no longer necessary in connection with the exchange possibility which has thus been made possible to remove the shank portion 1 from the presser bar 13. The exchanging of the foot sole which is placed into the mouth 11 from the front end is accomplished in a substantially more convenient manner than heretofore the exchange of the entire foot together with the shank which has to be released from the presser bar due to the crowded space resulting from the presser bar by carefully swinging the shank laterally of the presser bar. In order to prevent that the mouth 7 in open condition cannot be swung too far an abutment pin is provided which rests against the edge 15 of the shank 1. A further pin 16 is provided in the shank in order to continuously retain the catch member 6 with its throat portion '7 in the range of the slot 8 of the shank member 1.

Having now described our invention with reference to the embodiment illustrated, we do not wish to be limited thereto, but What we desire to protect by Letters Patent of the United States of America is set forth in the appended claims.

We claim:

1. Presser foot for sewing machines comprising a shank member presenting a bottom portion, a rearward portion provided with a pivot pin and a forward end defining a mouth portion, a soie portion adapted to be pivotally mounted on said shank member and interlocking means comprising a coupling link movably mounted longitudinally of said bottom portion of said shank member, a finger lever pivotally mounted by means of said pivot pin on the rearward portion of said shank member and a joint pin operativel linking said finger lever to one end of said coupling link for movement about said pivot pin, said sole portion having a bearing joint pin extending transverse? ti ereto' adapted to engage said mouth portion and said catch lever having a throat portion at the free end thereof; said coupling link bei movable with said finger lever to engage said bearin joint by means of said throat portion and retain said sole portion in engagement with said mouth portion for rocking movement about said bearim joint pin during the locked condition of the device.

2. Presser foot for sewing machines comprising a shank member presenting a bottom portion, a rearward portion provided with a pivot pin and a forward end defining a mouth portion, a sole portion adapted to be pivotally mounted on said shank member and interlocking means comprising a coupling link movably mounted longitudinally of said bottom portion of said shank member, a finger lever pivotally mounted by means of said pivot pin on the rearward portion of said shank member and a joint pin operatively linking said finger lever to one end of said coupling link for movement about said pivot pin, said sole portion having a bearing joint pin extending transversely thereto adapted to engage said mouth portion and said catch lever having a throat portion at the free end thereof; said couplin link being movable with said finger lever to engage said bearing joint pin by means of said throat portion and retain said sole portion in en gagernent with said mouth portion for rocking movement about said bearing jo'int pin during the locked condition of the device, said finger lever and said one end of said coupling link each having a portion ofi'set at an angle of substantially 90 constituting a toggle joint adapted to be locked to securely retain said bearing pin against said mouth portion.

3. Presser foot for sewing machines comprising a shank 4 member presenting a bottom portion, a rearward portion provided with a pivot pin and a forward end defining a mouth portion, a sole portion adapted to be pivotally moun ed on said shank member and interlocking means comprising a coupling link movably mounted longitudisaid bottom portion of said shank member, a ringer lever pivotally mounted by means of said pivot pin on the rearward portion of said shank member and a joint pin operatively linking said finger lever to one d of sa coupling link for movement about said pivot a s id sole portion having a bearing joint pin extending transversely thereto adapted to engage said mo'uth portion and said catch lever having a throat portion at the free end thereof; said coupling link being movable with finger lever to engage said bearing joint pin by means said throat portion and retain said sole portion in enment with said mouth portion for rocking movement L0 eilect a locking action on said finger lever and thereby said catch lever.

4. Presser foot for sewing machines comprising a shank member presenting a bottom portion, a rearward portion provided with a pivot pin and a forward end defining a mouth portion, a sole portion adapted to be pivo'tally mounted on said shank member and interlocking means comprising a coupling link movably mounted longitudinally of said bottom portion of said shank member, a finger lever pivotally mounted by means of said pivot pin on the rearward portion of said shank member and a joint pin operatively liking said finger lever to one end of said coupling link for movement about said pivot pin, said sole portion having a bearing joint pin extending transversely thereto adapted to engage said mouth portion and said atch lever having a throat portion at the free end thereof; said coupling link being movable with said finger lever to said bearing joint pin by means of said thro'at portion and retain said sole portion in engagement With said outh portion for rocking movement about said bearing joint pin during the locked condition of the device, said finger lever and said one end of said coupling link each g a portion offset at an angle of substantially 90 constituting a toggle joint adapted to be locked to securely tain said bearing pin against said mouth portion, said vct i '11 having an eccentric ofi'set operative in the locking position of said finger lever to effect a locking action on said. finger lever and thereby on said catch lever, and said fin er lever, said catch lever, said pivot pin and said joint 'n having lateral dimensions confined within the lateral mits of said shank portion.

References Qited in the file of this patent UNITED STATES PATENTS 9i8,lt30 Johnson Apr. 13, 1909 1,991,752 Karla Mar. 14, 1933 2,814,266 Marshall Nov. 26, 1957 ronaron PATENTS 15,590 Germany Sept. 29, 1881 156,294 Sweden Sept. 25, 1956