US3682118A - Adapter device for stitching letters - Google Patents

Abstract

An adapter device removably mounted on a sewing machine bed for stitching letters of a kind but different in size with the use of a pattern cam assembly including a pair of transmitters to transmit the oscillations of cam followers tracing said pattern cam assembly to levers for moving a stitch frame two dimentionally in variable amplitudes.

Description

United States Patent Taketomi 1151 3,682,118 1451 Aug. 8, 1972 1541 ADAPTER DEVICE FOR STlTCl-IING LETTERS 72 Inventor: Bunsaku Talretomi, 56-141 Azalshikane, Oaza-lwasaki, Nisshinc110, Aichi-gun, Aichi-ken, Japan 221 Filed: July 8, 1970 211 App1.No.: 53,101

52 u.s.c1. ..'....-....112/102 511 1111.01 ..D05c 3/02 [58] FieldofSearch ..112/102, 103

[56] References Cited UNITED STATES PATENTS 1,575,285 3/1926 Sibbardetal ..112/102 3,082,720 3/1963 Sanbe ..112/102 3,096,737 7/1963 Bono ..l 12/ 103 X 3,112,718 12/1963 Bond ..112/102 3,168,064 2/1965 Fresard et a1 ..112/102 3,516,373 6/ 1970 Maeda ..112/102 Primary Examiner-Alfred R. Guest Attorney-Linton & Linton [57] ABSTRACT An adapter device removably mounted on a sewing machine bed for stitching letters of a kind but different in size with the use of a pattern cam assembly including a pair of transmitters to transmit the oscillations of cam followers tracing said pattern cam assembly to levers for moving a stitch frame two dimentionally in variable amplitudes.

5 Clains, 7 Drawing Figures mmm 8 m2 SHEET 1 [IF 3 INVENTOR Y Bl/IVSHKU TAKE TOM/ ATTORNEYS PATENTEUA B 8 I SHEET 2 BF 3 INVENTOR BUNSRKU TAKETOMI BY M /M ATTORNEYS PATENTEU 8 I972 3,682, 1 l8 sum 3 [IF 3 Fig.5

m'EmoR BUNSRKU TA KETOM/ BY M w/M ATTORNEYS ADAPTER DEVICE FOR STITCHING LETTERS This invention relates generally to a sewing machine and more particularly to an improvement in an adapter device to be set to the sewing machine for stitching letters.

In the conventional adapter device of this type, a pair of levers tracing a pattern cam assembly actuate a stitch frame, on which a material to be stitched is fixed, on a sewing machine bed. However it has been impossible to stitch many letters of one kind but of different sizes using aspecified pattern cam assembly because levers for moving the stitch frame touch the pattern cams directly and the amplitudes of the oscillatory movements of the levers are not adjustable.

An object of the present invention is to provide an improved adapter device in which a pair of intermediate transmitters are located between the cam followers and the levers to move the stitch frame in order to vary amplitudes of oscillations of the cam followers whereby letters different in sizes or in the ratio of height and breadth can be doublicated froma specified pattern cam assembly.

The above and other objects of the present invention will be apparent from the following detail descriptions with respect to preferred embodiments and claims taken along with accompanying drawings in which:

FIG. 1 is a plane view of an adapter device embodying the present invention set to a sewing machine bed with some parts broken away a cover member being taken away,

FIG. 2 is a plane view showing another combination of a mechanism for moving the stitch frame and the intermediate transmitters,

FIG. 3 is a view showing various letters to be duplicated from a specified pattern cam assembly,

FIG. 4 is a perspective view of a sewing machine to be equipped with the adapter device according to the present invention,

FIG. 5 is a plane view of another embodiment of the intermediate transmitter,

FIG. 6 is a sectional view taken along the line 55 in FIG. 5 and FIG. 7 is a perspective view showing the mechanism for displacing intermediate transmitters.

Referring to the drawings, in which similar reference numerals identify corresponding parts throughout several views, a sewing machine comprises a bed 10 secured to a machine frame not shown, a standard 11 upstanding from said bed, a bracket arm 12 and a head '13 earring a needle 14 reciprocable vertically. A looper drive shaft 15 is journaled under the bed 10 and is adapted to be oscillated azimuthally from a main shaft (not shown) in the bracket arm 12 through a crank 16 secured to one end of the looper drive shaft 15 and through a pitman l7 pivotally engaging the crank 16 which pitrnan is reciprocated vertically in the standard 11 in accordance with the rotation of the mainshaft. The feed speed i.e. the period of the oscillilation of the looper drive shaft 15 is adjusted by a feeder dial 18 provided on the standard 11. The upper portion of a pinion 19 projects vertically through a hole 20 bored through the right hand portion of the bed 10. The pinion 19 and a ratchet wheel 21 are secured to a common vertical shaft 22 which is held by a frictional force in a degree that it can be rotated when given an appropreate torque. The ratchet wheel 21 is engaged by a piston rod 23 which is pivotally connected at its one end to a connector 24 secured to the intermediate portion of the looper drive shaft 15. Thus, the ratchet wheel 21 is rotated by the reciprocating piston rod 23 when the looper drive shaft 15 is oscillated. Next in an adapter device 25 to be mounted on the bed 10, a base plate 26 is provided with a fitting 27 and an elongated hole 28 to pass a mounting screw 29 as means for positioning the base plate 26 on the bed 10 and has a pinion hole 30 to loosely pass the pinion 19. A case member 31 is fixed on the base plate 26 so as to cover the pinion hole 30. A thin guide member 32 is secured on the base plate 26 alongthe longitudinal direction of the case member 31 and the height of the guide member 32 is made smaller than that of the projecting portion of the pinion 19 when the adaper device is mounted on the bed 10. A pattern cam assembly 33 comprises a slide plate 34 adapted to be slidable between a side wall 31'of the case member and the thin guide member, a lateral pattern cam 36 35 secured on the slide plate 34, and a longitudinal pattern cam 36 secured on the lateral pattern cam 35 and having at its one longitudinal side a rack 19 to be in gear with the pinion 19. Curved surfaces 35 and 36' of the pattern cam assembly 33 are formed according to the conventional art so that a pair of cam followers to be described below are given necessary oscillatory movements to duplicate letters of a predetermined kind and size. A pair of cam followers 37 and 38 are pivotally mounted by a common pivot 39 on the bed and their extended free ends 37 and 38 contact with curved surfaced 35' and 36' respectively through an opening (not shown) through the wall 31. A lateral linear lever 40 and a longitudinal angle lever 41 with two arms 41 and 41" are pivotally mounted on the plate 26 by a common screw 42. A circular spring 42 is mounted between the arm 41 and the lateral lever 40 in order to bias them in a manner that tend to move said arm and lever apart from each other but their displacements are limited by a spiral spring 42" secured on the base plate 26. A drive link 43 is pivotally connected at its one end to the end portion of the lateral lever 40 by a pin 40' and is secured at the other end to a stitch frame 44 on which a material to be stitched is secured. A connecting link 45 is pivotally connected to the arm 41" of the longitudinal lever 41 and to the drive link 43 by pins 46 and 46'. Thus it is understood that the stitch frame 44 is moved laterally on a needle plate 47 when the lateral lever 40 is rotated around the screw 42 and longitudinal when the iongitudinal lever 41 is rotated to rotate the drive link 43 around the pin 40'. The longitudinal and lateral travels of the stitch frame 44 are made proportional to those of the arm 41" at 46 and of the lever 40 at 40" respectively. In a mechanism for varing the style of letters to be stitched, a dial disk 48, which is to be fixed on a cover member 52, is positioned over the base plate 26 around a post 49 set up on the base plate 26. Between the disk 48 and a base plate 26, two rotary levers 50 and 51 of different length are carried by coaxial hollow cylindrical shafts 50 and 51 respectively which are held around the post 49 at an arbitrary angular position by frictional force, but are rotatable if actuated by a hand. On the dial disk 48 a pair of pointers 50" and 51" are secured to shafts 50 and 51 respectively to indicate the angular positions of the rotary lever 50 and 51 respectively. An intermediate transmitter 53 is pivotally connected to the rotary lever 50 at its one end and at the other end has a laterally extending contact piece 53' which contacts with the side surfaces of the cam follower 37 and the lateral lever 40. A similar intermediate transmitter 54 with a laterally extending contact piece 54 is connected to the rotary lever 51 and engages the cam follower 38 and the arm 41'. The operation of the above construction is as follows. The adapter device is mounted on the bed and the pinion 19 projects through the holes 20 and 30. The pattern cam assembly 33 for stitching a letter N, for example, is

inseted between the wall 31 and the guide member 32 and the rack 19' comes in gear with the pinion l9. Pushing astarter handle 55 formed integrally with the lever 40 towards the intermediate transmitters 53 and 54 and starting the sewing machine, a sewing machine operator can stitch a letter N as shown by 57in FIG. 3 on the material 56 carried by the stitch frame 44 with the needle 14 reciprocating transversely. If the operater rotates both of the rotary levers 50 and 51 clockwise from the positions shown if FIG. 1, the contact pieces 53" and 54' slide towards the pivot 39 along the side surfaces of the followers 37 and 38 respectively. Thus, the oscillations of followers 37 and 38 are transmitted in more attenuated amplitudes to the lateral and longitudinal levers 40 and 41. With this situation of the transmitters, a letter proportionally reduced as shown by 58 is stitched. If only the rotary lever 50 is rotated clockwise, only the transmitter 53 slides towards the pivot 39 and only the amplitude of the oscillation of the lever 40 is reduced. In this case, a letter reduced in breadth as shown by 59 is stitched. If only the rotary lever 51 is rotated clockwise, a letter reduced in height as shown by 60 is duplicated. The oscillating amplitudes of cumfollowere 37 and 38 can be amplified, too by the counterclockwise rotation of the rotary levers 50 and 51.

The mechanism for moving the stitch frame 44 can be replaced by that shown in FIG. 2. In this mechanism, a longitudinal rod 61 and a lateral rod 62 are slidably supported in fixed aperture members 63. To one end portion of these rods are secured contact members 61' and 62' in contact with contact pieces of the transmitter 53 and 54 respectively. The other end of the rod 61 is pivotally connected to an arm of an angle lever 64 rotatably supported by a pin 65. A guide rod 66 is slidably inserted in aperture members 67'and has a bifurcated holder 68 secured at its one end, which holder is usually biased by a compression coil spring 66' to contact with the other end of the rod 62. The holder 68 holds a shaft 69 at right angle to the rod 66. A circular stitch frame 70 with two extensions 70 and 70" has the shaft 69 slidably inserted through holes formed in said extensions. The extention 70" engages the other arm of the angle lever 64 and is usually biased to rotate the lever 64 clockwise by a coil spring 71. Thus the rods 61 and 62 reciprocate as the transmitters 53 and 54 oscillate and move the stitch frame 70 longitudinally and laterally. As a means to transmit the amplitude of the cam follower, another construction shown in FIGS. 5 and 6 is possible. A cam follower 72 is provided with grooves 73 on both sides. A bifurcated transmitter 74 is slidably mounted on cam follower 72 ffaiisilifitf ifiiiiiliiifor"aifiiofiifvfifii'ii?2133% rod 75 is pivotally connected to the transmitter 74 and a rotatable disk 76. The rotation of the disk 76 slides the transmitter 74 towards or away from a pivot 77 thereby to attenuate or amplify the amplitude of the oscillation of the follower 72.

As is clear from foregoings it is possible according to the present invention to stitch letters of a kind but different in sizes using a specified patterncum assembly. Thus letters of various styles such as broad one or tall one are doublicated freely on a material to be stitched by changing positions of the intermediate transmitters 53 and 54 Having presented the disclosure of the invention, what I claim is:

1. An adapter capable of being detachably mounted on a sewing machine having a machine bed and a looper drive shaft driven pinion on said bed, for stitching designs on a work piece comprising a base plate mountable on the sewing machine bed and having an opening for the looper drive shaft driven pinion to extend therethrough, a cam assembly having a rack for meshing with said pinion and two cam patterns, a work supporting frame, a lever pivotally mounted on said base plate, a link connecting said lever to said work frame for imparting lateral movement thereto, a second lever pivotally mounted on said base plate, a second link connecting said second lever to said first link for imparting longitudinal movement to said work frame, cam followers levers pivotally mounted on said bed plate and each in contact with a different one of said cam patterns, motion transmitting means pivotally supported on said base plate and interposed between said cam followers levers and said first and second mentioned levers for motion transmission and means for changing the pivot point of said motion transmitting means and thereby their points of contact with said cam follower levers and said first and second mentioned levers.

2. An adapter as claimed in claim 1 wherein said motion transmitting means includes a pair of adjustably mounted transmitter levers having lateral contact pieces slideably contacting said carn follower lever and said first and second mentioned levers.

3. An adapter as claimed in claim 2 wherein said second means includes a pair of rotary levers pivotally mounted around a common axis and each pivotally connected to a different one of said transmitter levers, a pair of pointers and means connecting each pointer to a different one of said rotary levers for indicating the angular positions of said rotary levers.

4. An adapter as claimed in claim 1 in which said first lever is an angular lever, said second lever is a straight lever and a common pivot pivotally supports a corner portion of said first lever and an end of said second lever.

5. An adapter as claimed in claim 4 including resilient means tending to pivot said first and second levers from one another and further resilient means tending to pivot said second lever towards said first lever.

Claims (5)

1. An adapter capable of being detachably mounted on a sewing machine having a machine bed and a looper drive shaft driven pinion on said bed, for stitching designs on a work piece comprising a base plate mountable on the sewing machine bed and having an opening for the looper drive shaft driven pinion to extend therethrough, a cam assembly having a rack for meshing with said pinion and two cam patterns, a work supporting frame, a lever pivotally mounted on said base plate, a link connecting said lever to said work frame for imparting lateral movement thereto, a second lever pivotally mounted on said base plate, a second link connecting said second lever to said first link for imparting longitudinal movement to said work frame, cam followers levers pivotally mounted on said bed plate and each in contact with a different one of said cam patterns, motion transmitting means pivotally supported on said base plate and interposed between said cam followers levers and said first and second mentioned levers for motion transmission and means for changing the pivot point of said motion transmitting means and thereby their points of contact with said cam follower levers and said first and second mentioned levers.

2. An adapter as claimed in claim 1 wherein said motion transmitting means includes a pair of adjustably mounted transmitter levers having lateral contact pieces slideably contacting said cam follower lever and said first and second mentioned levers.

3. An adapter as claimed in claim 2 wherein said second means includes a pair of rotary levers pivotally mounted around a common axis and each pivotally connected to a different one of said transmitter levers, a pair of pointers and means connecting each pointer to a different one of said rotary levers for indicating the angular positions of said rotary levers.

4. An adapter as claimed in claim 1 in which said first lever is an angular lever, said second lever is a straight lever and a common pivot pivotally supports a corner portion of said first lever and an end of said second lever.

5. An adapter as claimed in claim 4 including resilient means tending to pivot said first and second levers from one another and further resilient means tending to pivot said second lever towards said first lever.

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