US3411468A

US3411468A - Blindsititch sewing machine

Info

Publication number: US3411468A
Application number: US557718A
Authority: US
Inventors: Gerald C Roth
Original assignee: Union Special Machine Co
Current assignee: Union Special Machine Co
Priority date: 1966-06-15
Filing date: 1966-06-15
Publication date: 1968-11-19
Anticipated expiration: 1985-11-19
Also published as: GB1166127A; DE1685078A1

Description

Nov. 19, 1968 G. c. ROTH 3,411,468

BLINDSTITCH SEWING MACHINE Filed June 15, 1966 12. Sheets-Sheet l Nov. 19, 1968 cs. c. ROTH BLINDSTITCH SEWING MACHINE 12 Sheets-Sheet 2 Filed June 16, 1966 NOV. 19, 1968 G, c, ROTH 3,411,468

BLINDSTITCH SEWING MACHINE Filed June 15, 1966 l2 Sheets-$heet 3 FIG.4.

G. C. ROTH Nov. 19, 1968 BLINDSTITCH SEWING MACHINE l2 Sheets-Sheet 4 Filed June 15, 1966 NOV. 19, 1968 G, c, ROTH BLINDSTITCH SEWING MACHINE l2 Sheets-Sheet 5 Filed June 15, 1966 Nov. 19, 1968 G. c. ROTH BLINDSTITCH SEWING MACHINE l2 Sheets-Sheet 6 Filed June l5, l9

Nov. 19, 1968 G. c. ROTH BLINDSTITCH SEWING MACHINE l2 Sheets-Sheet '7 Filed June 15, 1966 C. ROTH BLINDSTITCH SEWING MACHINE Nov. 19, 1968 12 Sheets-Sheet 8 Filed June 15, 1966 G. C. ROTH Nov. 19, 1968 BLINDSTITCH SE WING MACHINE l2. Sheets-Sheet 9 Filed June 15. 1966 G. C. ROTH BLINDSTITGH SEWING MACHINE Nov. 19, 1968 12 Shets-Sheet 10 Filed June 15. 1966 Nov. 19, 1968 5. c. ROTH BLINDSTIT CH SEWING MACHINE 12 Sheets-Sheet 11 Filed June 15, 1966 \\\\&\\\\\ Fillflflllllllflllllfllll (3. C. ROTH Nov. 19, 1968.

BLINDSTITCH SEWING MACHINE Filed June 15. 1966 l2 Sheets-Sheet 12 F I I I UI n l l l United States Patent 3,411,468 BLINDSTITCH SEWING MACHINE Gerald C. Roth, Bethpage, N.Y., assignor to Union Special Machine Company, Chicago, Ill., a corporation of Illinois Filed June 15, 1966, Ser. No. 557,718 17 Claims. (Cl. 112-178) ABSTRACT OF THE DISCLOSURE A blindstitch sewing machine having a rockable Work support over which the material to be stitched is advanced, said work support being disposed substantially forwardly of a vertically extending standard having a horizontally extending arm which carries a main drive shaft, this arm extending in a direction parallel with the work support and the axis about which the work support is rocked. A rotary shaft is provided in the work support for operating a node former, this shaft being driven from the main drive shaft through a toothed belt connecting a toothed pulley on the main drive shaft with a toothed pulley on the shaft within the work support. Any of various node forming devices may be provided in the work support for operation by the rotary shaft therein.

This invention relates to high-speed blindstitch sewing machines, and more particularly to such machines that are capable of operation at high speeds without creating objectionable vibrations of the frame structure and operating mechanism thereof.

Machines of the type contemplated b the invention have frame structures involving a base having a portion thereof or a member carried thereby extending horizontally in front of the operator of the machine and a portion extending rearwardly away from the operator, a vertical standard rising upwardly from the rear portion of said base, an arm extending horizontally from the upper end of said vertical standard substantially parallel with the horizontally extending portion of said base, or the member carried thereby, and an overhanging arm extending forwardly from said first mentioned arm, said forwardly extending arm having its free end positioned above said first mentioned portion of the base or said member carried thereby. The machines here involved have stitch forming devices carried by said overhanging arm and node forming mechanism carried by said first mentioned portion of the base or the member carried thereby. Said portion of the base, or the member carried thereby, is provided with a node forming mechanism of one or another of a variety of different forms. A main drive shaft extends longitudinally of said horizontally extending arm of said frame and connections are provided from said main drive shaft for operating said stitch forming mechanism and said node forming mechanism.

A feature of the invention resides in the provision of novel connections from said main drive shaft to the note forming mechanism which is of such character as to eliminate the necessity of cumbersome, vibration producing parts to operate the node forming mechanism in properly timed relation to the operation of the stitch forming devices. In achieving that purpose, at least one toothed, positive drive belt is provided in the connections from said drive shaft to the node former. At least one such drive belt is of substantial length and extends forwardly in a substantially horizontal direction to replace rigid metallic members previously employed for this purpose. Said drive belt is connected with a pulley secured to a shaft in said base or the member carried thereby adapted to operate said node former.

3,411,468 Patented Nov. 19, 1968 ice Another feature of the invention is the selective provision of one or another of a variety of different node forming mechanisms, such as a vertically reciprocatory node former, or a rotary node former, or a plurality of reciprocatory node formers effective at different times during a cycle of operation of the machine. Other types of node formers may be employed if desired.

Still another feature of the invention is the provision of special belt driving connections between the main drive shaft and the node former, or plurality of node formers, within an enclosed portion of the frame structure in a manner not to interfere with the easy and simple manipulation of the work by the operator. In achieving this purpose of the invention it has been found necessary or desirable to provide an intermediate shaft, hereinafter referred to as a stub-shaft, between the main shaft and the base portion of the frame of the machine within the vertically rising standard portion of the frame. This makes it unnecessary to provide a belt connection directly from the main drive shaft to the node former drive shaft. If the node forming mechanism is of the vertically reciprocatory type, the main drive shaft and the intermediate shaft, or stub-shaft, may be simply connected by gearing. However if the node forming mechanism is of the rotary type it has been found desirable to connect the main drive shaft with the intermediate shaft by means of a toothed belt cooperating with pulleys on the two shafts so that the latter will rotate in the same direction, and thereby impart rotation to the node former drive shaft in the same direction.

While the invention is adapted for use in connection with a machine having a stationary work support member, it has been found particularly advantageous for use in connection with a machine having a rockable work support, the latter being rocked about a horizontal axis spaced from, but parallel with, the node former carrying or drive shaft. In such a machine, when the work support is rocked about its fixedly mounted carrying shaft, the toothed belt connection from the main drive shaft to the node former drive shaft will readily take care of relative movement of the axes of these two shafts in bringing about the proper selected position of the node former in relation to the work for the accommodation of work of different thicknesses and also for the production, whenever desired, of skip stitches in the seam being produced. To effectively take care of these changes in the relative position of the axis of the main drive shaft and the node former drive shaft, and in fact for insuring the proper tensioning of the toothed belt which interconnects the two shafts, there is provided a spring urged arm carrying a roller adapted to cooperate with one run of the toothed belt.

A still further feature of the invention is the provision of dual means for adjusting the normal position of the rockable work support to adapt it for proper action on work of different thicknesses. One of the adjusting means is in the form of a screw member carried by the forward end of the base of the machine and adapted to cooperate with the end of an adjusting spring urged rod within the base of the machine. At its opposite end this rod is connected with a two-armed lever within the vertical standard which has its upwardly extending arm arranged to cooperate with an inwardly and outwardly adjustable member extending through the forward wall of the vertical standard, preferably at an acute angle to the vertical. This second adjustable control over the position of the work support is provided with an indicating finger arranged to cooperate with a dial that serves to indicate accurately the precise adjustment of the work support. Thus the screw member mentioned above enables a rough adjustment of the work support and the second adjustable control enables a fine adjustment of the work support, with a definite indication of its position.

With the foregoing objects and features of the invention in view, certain preferred embodiments of the same will now be described in detail in reference to the accompanying drawings, in which:

FIG. 1 is a front elevational view of a machine embodying the invention, with certain parts broken away and shown in section;

FIG. 2 is a vertical sectional view through the machine taken along the plane of the line 2-2 of FIG. 1;

FIG. 3 is a perspective view of certain elements shown in FIG. 2;

FIG. 4 is an elevational view of the machine as seen from the left in FIG. 1, with portions shown in vertical section taken along the line 4-4 of FIG. 1;

FIG. 5 is an elevational view of the machine as seen from the right in FIG. 1, with certain parts shown in vertical section along the line 55 of FIG. 1;

FIG. 6 is a plan view of the machine with certain parts broken away and shown in horizontal section;

FIG. 7 is an exploded perspective view of the node former and its driving means;

FIG. 8 is a vertical sectional view of a portion of the work support, taken along the line 88 of FIG. 9;

FIG. 9 is a plan view of a portion of the work support with certain parts shown in section;

FIG. 10 is a vertical sectional view through a portion of the work support of the machine, taken along the line 10-10 of FIG. 11, and shows a modified form of node forming mechanism;

FIG. 11 is a plan view of the portion of the work support shown in FIG. 10;

FIG. 12 is an exploded perspective View of one of the node forming elements embodied in FIG. 10;

FIG. 13 is a view partly in front elevation and partly in vertical section through a machine embodying a further modified form of node forming mechanism;

FIG. 14 is a plan view of a portion of the work support of the machine shown in FIG. 13, as seen along the line 1414 of FIG. 13;

FIG. 15 is a vertical section taken along the line 15'-15 of FIG. 13;

FIG. 16 is a plan view of a portion of a machine incorporating another embodiment of the invention;

FIG. 17 is an elevational view of the machine shown in FIG. 16, with a portion shown in vertical section, taken along the line 1717 of FIG. 16;

FIG. 18 is a plan view of a further modified form of the invention, with certain parts broken away and other parts shown in horizontal section;

FIG. 19 is a vertical sectional view taken in different planes indicated by the line 1919 of FIG. 18;

FIG. 20 is a plan view of a portion of a machine embodying a further modified form of the invention; and

FIG. 21 is a vertical sectional view taken in different planes indicated by the line 21-21 of FIG. 20.

Referring now to the drawings, one embodiment of the invention is illustrated in FIGS. 1-9 inclusive. It comprises a frame having a base portion 10 extending rearwardly from the position in which the operator is located in the use of the machine. Such base portion of the frame has a laterally disposed part in front of the operator, which rises vertically to a suitable extent to carry a work supporting member to be described. At its rear end the base portion has connected therewith, preferably integrally, a vertical standard 11 from which there extends laterally, substantially parallel with the front portion of the base, an overhanging arm 12. Adjacent its free end, the overhanging arm 12 carries a forwardly extending arm 13 the front end of which is positioned over a portion of the work supporting member. The work supporting member may be rigidly connected with the base portion of the frame, but in the construction illustrated in FIGS. 1-9 inclusive it comprises a rockable member 14. The latter,

as best shown in FIGS. 1 and 2, is adapted to be rocked slightly about a supporting shaft 15. This shaft may be secured to vertically extending portions 10a at the forward end of the base 10 in a manner known in the art. To insure proper location of the work support 14 in relation to the shaft 15, and to enable rocking of the work support about the shaft with a minimum of play and danger of vibration, the left end of the shaft (FIG. 1) is provided with a frusto-conical extension 15a cooperating with a frusto-conical surface in a downwardly extending wall of the work support 14. At the opposite end of shaft 15 there is provided an adjustable member 16 having screw-threaded engagement with an opening through a downwardly extending portion of work support 14 in alinement with the shaft 15, and having a. frusto-conical extension 16a cooperating with a frusto-conical surface provided in the right end of the shaft 15. This shaft may be adjusted longitudinally to a certain extent to position the work support in the desired location, and it is set in such position by screws 15b.

As shown in FIGS. 1 and 2 the work support member 14 has a downwardly extending skirt 14a at its front end in which is mounted a set screw 17 adapted to be locked in properly adjusted position by a nut 17a. The inner end of the set screw 17 cooperates with the end of a rod 18 mounted in the base of the machine frame. This rod has extending therethrough a pin 18a which cooperates with one end of a spring 18b that has its opposite end cooperating with a vertically disposed wall of the base member. At its right end (FIG. 2) the rod 18 is connected with a forked extension 19a at the lower end of a lever 19 rockable about a pivot 20 carried by the vertical standard of the frame. At its upper end the lever 19 is forked, as shown at 19b in FIG. 3, to straddle a screw member 22 carrying and serving to adjust a block or plate 21 adapted to be engaged by the upper end portion of lever 19. The position of said plate along the axis of screw 22 may be varied slightly through the turning of said screw. Such turning is accomplished by a knob 23 secured to the outer end of the screw and this knob, in a conventional manner, has a pointer 23a secured thereto which may be shifted in one direction or the other in relation to a dial 24 carried by the frame of the machine.

The arrangement described above enables the accurate adjustment of the desired normal position of the work supporting member 14 in accordance with the nature and thickness of the material being sewn. A rough adjustment for this purpose is accomplished by turning of the set screw 17, while a fine adjustment is then accomplished by turning of the knob 23. It will be appreciated that the spring 18b normally urges the upper end of lever 19 into engagement with the adjacent surface on the adjustable block 21, thus accurately positioning the left end of the rod 18 (FIG. 2). As shown in FIG. 4 a spring 25 is provided to normally rock the work supporting member in a clockwise direction, this being a counterclockwise direction of the member as shown in FIG. 2. The left end of spring 25 is secured to an adjustable screw 26 to enable some variation in the force of the spring. At its opposite end the spring is connected with a rod 27 having a pivotal connection with the downwardly extending skirt 14a of the work support. Such pivotal connection includes a stud 28 held in fixed relation to the skirt 14a by a set-screw 28a (FIG. 1). An adjustable screw 29 is also provided in the skirt 14a for cooperation with an upwardly extending portion of the base of the frame to limit the extent to which the work supporting member 14 may be rocked in a clockwise direction, as shown in FIG. 4. The foregoing features are similar to those disclosed in the patent to Taylor 3,105,450, granted Oct. 1, 1963. Other features of the first embodiment of the invention, to be described hereinafter, are also disclosed somewhat more fully in said Taylor patent.

Within the overhanging arm 12 there is suitably journaled a shaft 30 (FIG. 6) having secured thereto, at its outer end, a combined handwheel and pulley 31 by which the main drive shaft may be turned either by hand or by a suitable belt connection from a power source. Within the forwardly extending arm 13 of the frame there is journaled a rock shaft 32 arranged to be oscillated by an eccentric secured to the drive shaft 30, and appropriate connections therefrom, for moving a curved needle 33 along an arcuate path. Also within the forwardly extending ann 13 are connections from the main drive shaft 30 to a looper carrying member 34. The latter is arranged to reciprocate a looper 35 and to impart a suitable turning movement to the latter to make possible the formation of a desired stitch in cooperation with the curved needle 33. In addition connections, including a reciprocatory and oscillatory member 36 driven by eccentric means carried by the main drive shaft 30, serve to impart four-motion movements to a feed dog 37. The mechanism for accomplishing the foregoing purposes may be of the character disclosed in the above-mentioned patent to Taylor. It will be understood that when the machine is in operation the work will be advanced step by step by the feed dog 37 and a seam will be applied to the work by the curved needle 33 and looper 35.

The work to be stitched is introduced by the operator along the upper surface of the work support 14, and/ or its extension 14b, and passed along to the top surfaces of a pair of spaced platens 38 which are pivotally connected with flat surfaced portions 39a of vertically movable cylindrical elements 39. The lower portions of these cylindrical elements are hollow and are arranged to move vertically in passages 40 provided in the extension 14b of the work support. A spring 41 fitted within a cavity in the lower portion of each of the elements 39 serves to urge the latter upwardly. A screw threaded element 42 adjustably mounted in the lower end of the passage 40 in each of the elements 39 enables a variation in the upward force of the spring 41 that is imparted to each of the elements 39. When no work is being fed to the machine the platens 38 are urged against the lower surface of a fixed presser foot 43 carried by the frame above the work support extension 14b in the region of stitch formation. Guide plates 14c (FIGS. 6, 8 and 9) are secured by screws 14d to the top of the work supporting extension 14b in the region of the vertically movable rods or posts 39, and these plates are provided with passages through which the flat, reduced portions 39a of the posts are guided in their vertical movement and retained against turning. The forwardly extending portions of the platens 38, as shown at the left in FIG. 6 are reduced in width to provide a passage therebetween for a vertically reciprocatory node former 45. The upper end 45a of the node former has the configuration shown in FIGURES 4, 6 and 7 which enables it to pass freely upwardly through the space provided between the forwardly extending portions of the platens 38. Bearing sleeves 44 (FIGS. 1 and 4) are provided in openings 44a in the work support extension 14b to retain the node former 45 in its proper position for free vertical sliding movement. Within a hollow portion of the work support extension 14b means are provided for imparting the up and down movements to the node former. Such means includes a block 46 (FIGS. 1 and 7) secured by a set screw 46a to the node former, the latter having a flattened surface 45b adapted to cooperate with the inner end of the set screw 46a. A cylindrical extension 46b carried by the block 46 cooperates with an opening 47a in a link 47. The lower end of this link has an opening 4712 which cooperates with an eccentric pin 48a carried by a radially extending flange 48 secured to or integral with a rotary shaft 49 journaled in the work support 14 and its extension 14b.

Referring now to FIGURES 1, 5 and 6, the means for operating the shaft 49 comprises a pulley 51 secured to the main drive shaft 30 and a pulley 52 secured to one end of the shaft 49. These pulleys are of the toothed type and are interconnected by a toothed driving belt 53. In the embodiment now being described the pulleys and belt referred to are disposed outside of the frame of the machine in the region just to the left of the vertical plane indicated by line 5-5 in FIG. 1. Means are provided for taking up any slack in the belt 53, to insure proper driving of the shaft 49 from the main drive shaft 30-, even though the relative positions of these two shafts may vary slightly in a construction in which the work support 14 is such that the latter may be rocked to a certain extent about the axis of shaft 15. Also it is desirable to remove any slack present in the belt 53 to eliminate noise and vibration which might result from a slightly loose belt. The means for taking up the slack in the belt comprises a pulley 54 adapted to cooperate with the lower run of the belt. This pulley is mounted for rotation about a stud 54a carried by an arm 55 having its lower end (FIG. 5) mounted for slight swinging movement about a bolt 56 secured to the vertical standard of the frame. At a point intermediate the ends of the arm 55 there is provided a pin 57 which extends toward the frame of the machine and is adapted to receive and retain the hooked end of a spring 58. At its opposite end this spring is connected with a pin 59 extending outwardly from the vertical standard of the frame of the machine. To avoid any danger of work becoming engaged with the belt 53 and related parts, there is preferably provided a hood 60 suitably secured to the frame of the machine and of such form as to cover the portions of the belt and related means that might otherwise be exposed to the work.

In the foregoing embodiment of the invention no connections are provided from the main drive shaft for rocking the work support 14 to bring about the production of skip stitches, although such means of known character could be provided if desired. However, in any event, to facilitate the introduction and removal of Work from the machine it has been found desirable to provide a knee press member 61 (FIG. 6) connected with a forwardly, laterally and downwardly extending rod 62 having its forwardly extending portion journaled in the base portion of the frame of the machine. A torsion spring 63 normally urges the rod 62 into an inactive position with the knee press 61 located adjacent the right knee of the operator. When it is desired to rock the work support downwardly to a slight extent about the axis of the shaft 15, the operator simply presses the right knee against the member 61 to cause a counterclockwise rotation of the forwardly extending portion 62 of the rod. A corresponding rotation is imparted to an arm 64 secured to the inner end of the rod, and this arm is connected by a link or chain 65 with a downwardly extending portion of the work support 14.

It is believed that the mode of operation of the foregoing embodiment of the invention will be clear from the foregoing description. Sufiice it to say that as the work is being advanced through the stitch forming region along the top of the extension 14b of the work support, the node former member 45 will be reciprocated vertically once upon each cycle of operation of the machine. The region in which the portion 45a of the node former is lifted and lowered may be varied to a limited extent, to conform with the thickness of the work being dealt with from time to time, by the first rough adjustment of the location of the node former driving shaft 49 through the turning of set screw 17, and the finer adjustment of the location of shaft 49, and hence the uppermost position of the portion 45a of the node former, may be accomplished by turning the knob 33 in one direction or another. The driving connections from the main drive shaft 30' of the machine to the shaft 49 are comprised by the toothed belt and pulley members described, thus greatly simplifying the connections between these widely spaced shafts and also reducing greatly the tendency toward producing noise and vibration resulting from the mechanical, metallic connections previously employed for this purpose. In addition the tendency of the relatively heavy connections heretofore employed to overthrow, and thus cause variations in the stitches being formed, has been eliminated.

In FIGS. 10-12 there is shown a dual node former arrangement which may be incorporated in the machine of the general character described above, in lieu of the single node former in the latter. In this modification of the machine the work support is provided with a detachable extension 14b of substantially the same form as 1412 described above. The node former driving shaft 49', similar to the shaft 49 of the first embodiment, is arranged to be driven at one-half the speed of main drive shaft 30. This is accomplished by making the pulley 51 of only one-half the effective diameter of pulley 52. Shaft 49' is provided within the extension 1412' with a crank member 7 0, which may be integral with the shaft 49 or otherwise suitably secured to the latter. A crank portion 7 a of this member cooperates with a link 71 preferably having a split lower end with the parts thereof secured by screws 72 to provide a running fit in relation to the crank 70a. At its upper end the link 71 has an opening to receive a laterally extending pin 73a of a node former carrying member 73. The upper end of member 73 is of U-shaped configuration and adapted to receive the shank of a node former 73b which is secured in place by a set screw 73c. At the left end of the crank 70 (FIG. there is mounted a collar 74, in eccentric relation to the shaft 49' in the opposite direction from the eccentricity of part 70a of the crank. This eccentric collar 74 is secured to the crank 70 by a screw 75. A second :link 76 is mounted for relative turning movement in relation to the eccentric 74 and it has an opening at its upper end adapted to receive a pin 77a extending from the lower end of a second node former carrying member 77. The upper portion of member 77 is of U-shaped form and adapted to receive the shank of a node forming element 7712. This is fixedly secured to the member 77 by a screw 770.

'It will be appreciated that the foregoing modification of the machine provides a pair of

node forming elements

73b and 77b positioned side by side, adapted to be reciprocated at 180 apart in the cycle of rotation of the shaft 49. Thus the two node formers alternately move upwardly to engage the work and provide a node in it for the production of a desired seam. One of the node formers is active upon one revolution of the main shaft 30, and the other is active upon the next revolution of the main shaft. This arrangement is particularly useful in the formation of a zig-zag line of blindstitches.

In FIGS. 1315 there is illustrated a modified form of the invention utlizing a rotary node former rather than the vertically reciprocatory node formers of the embodiments above described. The machine as a whole may be substantially the same as that described in relation to the first embodiment, and may include a pivotally mounted Work support member 14" having an extension 14b" connected therewith, either integrally or by bolts or the like. A shaft 43", similar to shaft 49 of the first embodiment, is arranged to be driven from the main drive shaft through toothed pulleys 51" and 52" interconnected by a toothed belt 53". In the form of this embodiment of the invention as illustrated in FIG. 13, the pulley 51 has only one-half the effective diameter of the pulley 52", so that the shaft 49 is driven at only one half the angular speed of the main drive shaft of the machine.

Secured to the left end (FIG. 13) of the slraft 49" is a rotary node former 80 having two node forming sections Stla disposed diametrically opposite each other. This node former is secured to the shaft 49 by a set screw 8%. If desired the two oppositely disposed node forming sections 80a of the node former may be located in vertical planes that are spaced slightly from each other so as to enable the formation of a zig-zag line of blindstitches. When this is not desired, they may be located in the same vertical plane.

In this embodiment of the invention the vertically movable platens 38 of the first embodiment are replaced by pivotally mounted platens 38". These are rockably secured to two-armed levers 81 mounted for slight rocking movement about a stud 82 extending longitudinally of the work support extension 14b" and held in fixed position in relation to the latter by the set screw 82a. A screw 82b serves to retain the levers on the stud for rocking movement in relation thereto. Each of the levers 81 has connected with its lower end a spring 81a, the opposite end of which is attached to the frame of the extension 14b". The extent to which the levers 81 are rocked by the springs 81a is determined by set screws 81b having their inner ends cooperating with a portion of the frame structure of extension 14b". By suitable turning of the set screws 81b the uppermost position of the platens 38" may be varied slightly. As shown in FlG. 13 the node former carrying shaft 49" may, if desired, be journ-aled in a bearing sleeve 49a" suitably carried by the work support 14" or its extension 1412. At its left end (FIG. 13) the shaft 49" may be joumaled in a bushing 83 mounted in a suitable opening provided in a part of the frame structure of extension 14b.

Collars

84 and 84a secured to the shaft 49" serve to retain the latter in its desired longitudinal position.

It is believed that the mode of operation of the embodiment of the invention shown in FIGS. 13-15 will be clear from the foregoing description and that provided in relation to the first embodiment of the invention.

In FIGS. 16 and 17 a further modification of the overall construction of the machine embodying the invention is disclosed. An important aspect of this embodiment is the positioning of the pulleys and belt, which serve to interconnect the main drive shaft with the node former operating shaft, so that they all are enclosed within the main housing of the frame of the machine.

A combined handwheel and pulley 31, of the same character as the corresponding element in the first described embodiment, is positioned closely adjacent to the vertical standard of the frame of the machine, so that the main drive shaft 30" need not extend outwardly from the frame as far as in said first embodiment. Secured to the main drive shaft 30 by means of a screw 85a or a plurality of such screws is a toothed pulley 85 rotated by the main drive shaft. Within the work support member there is provided a shaft 49", generally similar to the shaft 49 of the first embodiment and suitably journaled in bearing means carried by the work support. To this shaft there is secured by means of a set screw 86a, or a plurality of such screws, a toothed pulley 86. A toothed belt 87 interconnects the

pulleys

85 and 86 to drive the shaft 49.

To enable the positioning of the various parts within the main frame structure, without interference with other parts contained therein, it has been found desirable to change the form and location of the means carrying a pulley 88 adapted to cooperate with the lower run of the belt to apply a suitable take-up action thereto. Thus pulley 83 is rotatably mounted on a stud carried by an arm 88a within the frame. This arm is mounted for pivotal movement about a pin or stud 88b extending inwardly from a vertical wall member (not shown) carried by the base of the frame. A spring 89 has one end connected with a pin 88c carried by the arm 88a intermediate its ends, and the opposite end of the spring is connected with a pin 99 extending from a vertically extending wall member of the frame.

The modified construction shown in FIGS. 16 and 17 may be incorporated in a machine embodying node formers of any of the types herein above described. The presently described modification of the invention will be understood as being embodied in a machine having the various features described in relation to the first embodiment. As illustrated, the work support 14" is piv0tal- 1y mounted on the base portion of the frame, but as has been previously stated the work support may be rigidly secured to the base of the frame if desired.

In FIGS. 18 and 19 there is shown a further modification of the driving connections from the main drive shaft to the node former actuating shaft. This embodiment includes the features of FIGS. 16 and 17 involving the location of the toothed pulleys and connecting belt within the frame structure of the machine. It adds to that aspect of the invention the provision of an intermediate shaft in the vertical standard for carrying the toothed pulley at that end of the belt drive connection. This enables the provision of a main frame structure which has the top surface of the base portion at a lower level than is possible with the construction shown in FIGS. 16 and 17.

The main drive shaft is designated 30*. To the outer end of this shaft is secured a combined handwheel and pulley 31 Secured to the main shaft 30 is a gear 91, the hub of which is provided with a set screw 91a for securing the same in set position on the shaft. Cooperating with gear 91 is a gear 92 secured to an intermediate shaft 93 directly below the shaft 30 To the shaft 93 is secured a toothed pulley 93a which is connected by a toothed belt 94 with a toothed pulley 95 secured to a node former driving shaft 49 carried by the work support 14 With this arrangement the pulley that is spring urged against the lower end of the toothed belt to take care of any slack and to insure proper cooperation of the belt with the toothed pulleys, is of the same general character as that shown in FIG. for the first embodiment above described. It comprises a pulley 96 rotatably mounted at the upper end of an arm 97 that is pivotally connected with the outer wall of the base by a screw 97a and a bolt 97b. A spring 98 has one end connected with an intermediate point on the arm 97 and its other end connected with a pin 98a carried by the frame of the machine.

In FIGS. 20 and 21 there is illustrated a modification of the embodiment shown in FIGS. 18 and 19, involving the substitution of a toothed belt drive from the main drive shaft to the intermediate shaft. Thus the gears 91 and 92 are replaced by toothed pulleys, one of which is shown at 100 as being secured to the main drive shaft 30 This pulley is connected by a toothed pulley 101 with a similar pulley (not shown) secured to the intermediate shaft 102. This lower pulley is substantially the same as a second pulley 103 secured to the intermediate shaft and which is connected by a toothed belt 104 with the node former operating shaft.

In FIGS. 20 .and 21 there is also shown a means for carrying a spring urged pulley 105 for taking care of any slack in the toothed belt 104. As here shown, the pulley 105 may be carried by an arm 106, the lower end of which is mounted on a screw stud 107 (FIG. 20) carried by a rod or stud 108 connected with the outer wall of the base. It should be understood that the arm 106, and .also arm 97 of FIG. 19, may, if desired, be connected at the lower end with a vertically extending member connected with the base of the frame in a location free from interference with other parts of the structure.

It will be understood that the node former mechanisms to be employed in connection with the driving means illustrated in FIGS. 20 .and 21 may be of any of the types herein above described. Thus they may be of the single or dual reciprocatory type or the rotary type, or they may be of any other suitable form.

With respect to the embodiment of FIGS. 18 and 19, 1

this is preferably not used in relation to a rotary type of node former. This is because the intermediate shaft 93 is rotated in the reverse direction from the main drive shaft, and accordingly the node former operating shaft 49 will be rotated in the opposite direction from the main drive shaft. Normally it is considered desirable to have a rotary node former so rotated that the node forming portion thereof, when active, moves in the direction of advance of the work being stitched. To .achieve this it is desirable 10 to have it rotated in the same direction as the main drive shaft.

While a number of embodiments of the invention have been shown and described in some detail, with suggested variations in certain aspects of the invention, it will be understood that other modifications may be made within the scope of the following claims.

I claim:

l. A blindstitch sewing machine having a frame including a base portion extending rearwardly at one side of the frame, the forward end of said base carrying rockable work supporting means extending laterally therefrom, a vertically extending standard at the rear end of said base, an overhanging arm extending laterally from said standard in substantially parallel relation to the work supporting means carried by said base, a second arm extending forwardly from said overhanging arm adjacent the free end of the latter to a position above said work supporting means, a main drive shaft extending longitudinally of said overhanging arm, work feeding and stitch forming means carried by said second arm adjacent the forward end thereof, connections from said drive shaft for operating said work feeding and stitch forming means, node forming means carried by said work supporting means adapted periodically to form nodes in the work as it is being advanced in the region of said stitch forming means, and connections from said drive shaft to said node forming means for operating the latter, said last mentioned connections comprising a toothed pulley rotatably mounted on said frame in the region of said vertical standard, a second toothed pulley rotatably mounted on said work supporting means, the axis of said second pulley being spaced from the axis about which said work support is rockable, and a toothed belt extending forwardly from said first mentioned toothed pulley to said second toothed pulley for driving the latter.

2. In a blindstitch sewing machine as set forth in claim 1, said first mentioned pulley being secured to said main drive shaft.

3. In a blindstitch sewing machine as set forth in claim 1, an intermediate shaft mounted in said vertical standard beneath said main drive shaft, connections from said drive shaft to said inter-mediate shaft for rotating the latter, said first mentioned pulley being secured to said intermediate shaft.

4. In a blindstitch sewing machine as set forth in claim 3, said connections from said drive shaft to said intermediate shaft comprising toothed pulleys secured to said two shafts, and a toothed belt interconnecting said last mentioned pulleys for rotating said intermediate shaft in the same direction as said drive shaft.

5. In a blindstitch sewing machine as set forth in claim 1, spring urged rotatable means cooperating with said toothed belt for removing slack from the latter and applying a desired tension thereto.

6. In a blindstitch sewing machine as set forth in claim 1, said rockable Work supporting means being pivotally connected with said base, and adjustable means for determining the normal position of said work supporting means in relation to said base.

7. In a blindstitch sewing machine as set forth in claim 6, said work supporting means being pivotally movable about an axis substantially removed forwardly from the axis of rotation of said second toothed pulley but parallel with the latter.

8. In a blindstitch sewing machine as set forth in claim 7, said connections from said main drive shaft to said node forming means for driving the latter comprising a rotary shaft in said work supporting means.

9-. In a blindstitch sewing machine as set forth in claim 8, said node forming means being secured to said last mentioned rotary shaft for rotation thereby.

10. Ina blindstitch sewing machine asset forth in claim 8, said node forming means comprising a reciprocatory member, and connections from said last mentioned rotary shaft for reciprocating said node fonming means.

11. In a blindstitch sewing machine as set forth in claim 8, said node forming means comprising a plurality of reciprocatory members, and connections from said last mentioned rotary shaft for reciprocating said node forming members in differently timed relation to each other.

12. In a blindstitch sewing machine as set forth in claim 8, said node forming means having a plurality of work engaging portions arranged to become active at different times during a revolution of said last mentioned rotary shaft.

13. In a blindstitch sewing machine as set forth in claim 8, said node forming means having two work engaging portions, and connections from said last mentioned rotary shaft to said node forming means adapted to move said work engaging portions into active position one after the other at about 180 intervals related to the rotation of said shaft.

14. In a blindstitch sewing machine as set forth in claim 13, said connections from said main drive shaft being arranged to drive said last mentioned rotary shaft at onehalf the angular speed of said main drive shaft.

15. In a blindstitch sewing machine as set forth in claim 1, a shaft rotatably mounted in said vertically extending standard with which said first mentioned toothed pulley is connected, and a shaft rotatably mounted in said work support with which said second mentioned toothed pulley is connected.

16. In a blindstitch sewing machine as set forth in claim 15, said node forming means being secured to said last mentioned rotary shaft for rotation therewith.

17. In a blindstitch sewing machine as set forth in claim 15, said node fonming means comprising a reciprocatory member, and connections from said last mentioned rotary shaft for reciprocating said node forming means.

References Cited UNITED STATES PATENTS 1,564,177 12/1925 Mueller 112-178 1,943,301 1/1934 De Voe 112178. X 2,718,862 9/1955 Parry 1121'78 X 3,105,450 10/1963 Tayor 112-178 HERBERT F. ROSS, Primary Examiner.