US2999471A

US2999471A - Adjustable guiding cam mechanism

Info

Publication number: US2999471A
Application number: US687139A
Authority: US
Inventors: Benink Christian Josep Marinus; Wenz Herbert
Original assignee: GM Pfaff AG
Current assignee: GM Pfaff AG
Priority date: 1956-10-09
Filing date: 1957-09-30
Publication date: 1961-09-12
Anticipated expiration: 1978-09-12
Also published as: DE1043044B; GB818125A; CH354653A; FR1182592A

Description

Sept 12, 1961 c. J. M. BENINK ETAL 2,999,471

ADJUSTABLE GUIDING CAM MECHANISM Filed Sp1.. 30, 1957 linited States Patent G 2,999,471 ADJUSTABLE GUIDING CAM MECHANISM Christiaan Joseph Marinus Benink and Herbert Wenz, Kaiserslautern, Pfalz, Germany, assiguors to G. M. Pfad AG., Kaiserslautern, Pfalz, Germany Filed Sept. 30, 1957, Ser. No. 687,139 Claims priority, application Germany Oct. 9, 1956 Claims. (Cl. 112-158) The invention relates to sewing machines of the zig-zag type and is more particularly concerned with a device for sewing decorative stitches, which comprises nests of pattern cams arranged upon a common rotatable shaft which control the lateral deections of the needle and also the stitch length for the forward and reverse stitches. A mechanism of the type in which the present invention may be utilized to advantage is illustrated in applicants copending application Ser. No. 687,730, tiled October 2, 1957, now U.S. Patent No. 2,887,968.

In sewing machines for decorative stitches known heretofore in which the stitch length is guided in addition to the lateral needle detlections, only one pattern cam disk is provided for the stitch length because the lever serving for transmitting the guiding movements to the feed dog is rockable only in ione plane due to structural limitations. It" it is desired to set up a pattern having a different stitch length, it is necessary to exchange the pattern cam disk for a different one.

It is an object of the invention to provide the possibility of optionally selecting among a plurality of mounted pattern disks for the stitch length fone disk for producing a plurality of patterns with the combination of one pattern disk for the stitch length and a pattern disk for the lateral needle deflections.

In accordance with the invention a plurality of pattern disks for the stitch length assembled in a nest are adjustable axially as well as in their circumferential relationship with respect to a follower which is movable in a plane and with respect to the pattern cam nest for the lateral needle dellections for selecting one pattern disk for the stitch length and for setting up an optional displacement of the guiding phases between both nests of cams.

For this purpose one of the nests of pattern cam disks is provided with spacing studs which are evenly distributed around a circle which is concentric with respect to the axis of rotation. These studs are adapted to engage corresponding groups of holes in the other nest of disks of different depths as well as of any desired number and distribution. The different depths of the individual groups of holes may for this purpose be a multiple of the thickness of the cam disks for the stitch lengths.

Other objects and advantageous features of the invention will become more apparent from the following description of an embodiment of the invention which is illustrated in the accompanying drawing in which:

FIG. l is a front view yof a sewing machine provided with the device in accordance with the invention;

FIG. 2 is a partial sectional view to an enlarged scale exposing the device in accordance with the invention;

FIG. 3 is a top view of the nest of pattern disks;

FIG. 4 is a cross section of the nests of disks taken along line IV-IV of FIG. 3; and

FIG. 5 is a view of the nested disks partly in section.

FIG. l generally illustrates the machine comprising the base plate 1, standard 2, arm 3 and head 4. The arm shaft 5 is journalled in the usual manner in the arm of the machine carrying the balance wheel 6 on its outwardly extending end and operatively connected at its other end to the reciprocable needle bar 7 which is arranged for deflection laterally to two sides. The lateral needle deiiections can be controlled in a known manner by means of the stitch width setting lever 8 and the stitch location adfice 2 justing lever 9. The mechanism for adjusting the stitch length which is operated by means of lever 10 is provided in the standard of the machine. The transmission bar 11 (FIG. 2) may also be coupled in a known manner to the stitch length setting means (not shown) by means of the setting lever 10 for automatically controlling the stitch length. The transmission bar 11 is mounted for pivotal movement about a pivot member 12 which is pivotally mounted in one arm 13 of an angular lever 14 which, in turn, is rockable on a. pivot member 15 secured in blocks 17 secured to a base plate 16. A link member 19 which is turned on itself at an angle of is joined by means of a screw 20 to the other arm 18 of angular lever 14, and the other end of the link member is joined by means of screw 21 to the offset arm 22 of the rockable lever 23. The lever 23 is rockable in a horizontal plane about a collar or pivot screw 24 and carries the follower member 26 endwise of a further offset arm 2S (see also FIG. 3). When the automatic control is cut in by means of shifting lever 10 the follower 26 is brought into engagement with the upper of the two pattern disks 27 and 2S provided for controlling the stitch length. The pattern disks are rotated in a known manner by way of a worm gear or the like (not shown) from the arm shaft 5 and a shaft 29 (FIG. 4). Shaft 29 is journalled in a stub 31 on the vbase plate 16 by means or' screws 30. A tubular support member 33 having a carrier pin 34 is provided upon Shaft 29 and secured thereto by means of a screw 32. A

sleeve 35 is slidingly received on the support member 33, having secured thereto cam disks 36 for guiding the lateral needle deflections, said cam disks being carried along by a pin 34 which is in engagement with a bore 37 in the lowermost of the cam disks.

At its upper end sleeve 35 is provided with a recess 38 which slidingly receives the lower end 39 of a manipulating member or sleeve 40 for axial and rotary adjustment. The pattern disks 27 and 28 for stitch'length are secured to the lower end 39 of the manipulating member or sleeve 49 which is provided with a shoulder or ring 41 at its lower` inner end for supporting a helical spring 43 which is disposed around a cylindrical lock member 42. The other end of spring 43 is supported against the head 44 of the lock member which is provided with a threaded bore 45 for engagement with a thread on the reduced upper p0rtion 46 of the shaft 29.

The nest of cam disks 36 for the lateral needle deflections is preferably provided with three pins 47 distributed evenly around the circumference of a circle which is concentric with the axis of rotation (FIGS. 3 and'4), which pins are in engagement with corresponding bores 48 which extend through both cam disks 27 and 28. In addition to bores 48 other through bores 48 are provided which are displaced by 30 with respect to bores 48. This makes it possible to displace the cam disks 27 and 28 with respect to the pattern disks 36 for the lateral needle deflections by 30, 120, 150, 240 and 270 degrees. This operation is effected by raising the sleeve 40 against the tension of spring 43, which removes the cam disks 27 and 28 from the pins 47 for rotation to the next throughgoing groups of

apertures

48 or 48.

Besides the two aforementioned groups, two additional groups of

apertures

49 and 49 are provided, spaced from each other by 30, which are only provided in disk 28. If the cam disks 27 and 28 are now shifted in the same manner by means of the manipulating sleeve 40 and are placed upon pins 47 with the

bores

49 or 49 which do not go through disks 27, the cam disks will assume a raised position of an amount corresponding to the thickness of a disk, thus causing the follower 26 which is rockable only in one plane to engage the lower cam disk 28 (FIG. 5). A plurality of groups of holes such as 49 and 49 makes it possible in the samemanner as set forth above to set up a predetermined phase relationship of the pattern disk 23 with respect to the set of disks 36.

We claim: y

l. A guiding cam mechanism for Zig-zag sewing machines of the type having a laterally deectab-le needle bar and a material 'feed dog adapted to be guided by said cani mechanism, said mechanism including need-le bar cam follower means operatively connected to and adapted to transmit lateral deflection impulses to said needle bar and feed dog cam follower means including asingle follower member operatively connected to and movable about a pivot in a single plane and adapted to transmit stitch length control impulses to said feed dog, said cam mechanism comprising a cam shaft, a first group of rotatable cam disks mounted on said cam shaft for engagement by said feed dog cam follower means and a second groupof rotatablefcam disks for engagement by said needle bar cam follower means mounted on said shaft coaxially with said first group, said first group being mounted around said shaft and being `axially and angularly adjustable relative to said second group and relative to said feed dog cam follower means, and setting means including a manipulating member mounted coaxially with said first group and operative to move said first group, thereby providing for optional phase displacement between said first group and said second group of Vdisks and for axially moving said first group to associate different cams yof said first group with said follower member.

Z, A guiding cam mechanism for Zig-zag sewing machines of the type having a laterally detlectable needle bar and a material feed dog adapted to be' guided by said cam mechanism, said mechanism including needle bar cam follower means operatively connected to and adapted to transmit lateral deflection impulses to said needle bar and feed dog cam follower means including a single follower member operatively connected to and movable about a pivot in a single plane and adapted to transmit stitch length control impulses to said feed dog, said cam mechanism comprising a cam shaft, a first group of rotatable cam disks mounted on said cam shaft for engagement by said feed dog cam follower means and a second group of rotatable cam disks for engagement by said needle bar cam follower means mounted on said shaft coaxially with said first group, said first group being mounted aroundsaid shaft and being axially and angularly adjustable relative to said second group and relative to said feed dog cam follower means, and setting means including a manipulating member mounted coaxially with said first group and operative to move said first group, thereby providing Ifor optional phase displacement between said first group and said second group of disks and for axially moving said first group to associate different cams of said first group with ,said follower member, one of said groups of disks being provided with pins distributed evenly around a circle concentric with the axis of rotation of the mechanism and the other of said groups of disks having corresponding bores adapted to receive said pins, said bores being provided in predetermined numbers of disks and extending into said disks t different depths.

3. A guiding cam mechanism for zig-Laag sewing machines of the type having a laterally deliectable needle bar and a material feed dog adapted to be guided by said cam mechanism, said mechanism Vincluding needle bar cam follower means operatively connected to and adapted to transmit lateral deflection impulses to said nedle bar and feed dog cam follower means including a single follower member operatively connected to and movable about a pivot in a single plane and adapted to transmit stitch length control impulses to said feed dog, said cam mechanism comprising a cam shaft, a first group of rotatable cam disks mounted on said cam shaft for engagement by said feed dog cam follower means and a second group'of rotatable cam disks for engagement by said needle bar cam follower' means mounted on said shaft coaxially with said first group, said first group being mounted around said shaft and being axially and angularly adjustable relative to said second group and relative to said feed dog cam follower means, and setting means including a manipulating member mounted coaxially with said first group and operative to move said first group, thereby providing for optional phase displacement between said first group and said second group of disks and for axially moving said first group to associate diderent cams of said first group with said follower member, one of said groups of disks being provided with pins distributed evenly around a circle concentric with the axis of rotation of the mechanism and the other of said groups ofdisks havingcorresponding bores adapted to receive said pins, said bores being provided in predetermined numbers of disks and extending into said disks to different depths, the difference in depth between bores corresponding to the'thickness of the disks associated with the stitch length.

4. A guiding cam mechanism for zig-zag sewing machines of the type having a laterally deflectable needle bar and a material feed dog adaptedy to be guided by said cam mechanism, said mechanism including needle bar cam follower means operatively connected to yand adapted to transmit lateral deflection impulses to said needle bar and feed dog cam follower means including a single follower member operatively connected to and movable about a pivot in a single plane and adapted to transmit stitch length control impulses to said feed dog, said cam mechanism comprising a cam shaft, a

' lfirst group of rotatable cam disks mounted on said cam shaft for engagement by said feed dog cam Ifollower means and a second group of rotatable oam disks for engagement by said needle bar cam follower means mounted on said shaft coaxially with said first group, said first group being mounted around said shaft and being axially and angularly adjustable relative to said second group and relative to said feed dog cam `follower, means, and setting means including a manipulating member mounted coaXially with said firstgroup and operative to move said first group, thereby providing for optional phase displacement between said first group and said second group of disks and for axially moving said first gro-up to associate different cams of said first group with said follower member, said first group of disks being associated with said mechanism for transmitting the" stitch length control impulses and 'being mounted above said second group of disks, and said manipulating member including a spring biased sleeve supporting said first group of disks and being axially and angularly movable relative to said second group.

5. A guiding cam mechanism for Zig-zag sewing maohines of the type having Ia laterally deflectable needle bar and a material feed dog adapted to be guided by said cam mechanism, said mechanism' including needle bar cam follower means operatively connected to and adapted to transmit lateral deflection impulses to said needle bar and feed dog cam follower means including a single follower member operatively connected to and movable about la pivot in a single plane and adapted to transmit stitch length control impulses to said feed dog, said cam mechanism comprising a cam shaft, a first group of rotatable cam disks mounted on said cam shaft for engagement by said feed dog cam follower means and a second :group of rotatable cam disks for engagement by said needle bar cam follower' means mounted on said shaft coaxially with said rst group, said first group being mounted laround said shaft and being axially and angularly adjustable relative to said second group Iand relative to said Vfeed dog cam follower means, and setting means including a manipulating member mounted coaxially with said first group and operative to move said first group, thereby providing for optional phase displacement between said first group and said second group of disks and for axially moving said first group 'to associate different cams of said first group .with said follower member, one of said groups of disks being provided with pins distributed evenly around a' circle concentric with the axis of rotation of the mechanism and the other of said groups of disks having corresponding bores 'adapted to receive said pins, said bores being provided in predetermined numbers of groups and extending into said groups to different depths, said rst group of disks being associated with said mechanism for transmitting the stitch length control impulses and being mounted above said second group of disks, and said manipulating member including `a spring biased sleeve supporting said lfirst group of disks and being axially and angularly movable relative to said second group.

References Cited in the le of this patent UNITED STATES PATENTS Italy July 8, 1955