US2548815A - Rotary hook mechanism for sewing machines - Google Patents

Description

A ril 10, 1951 c. H. PETSKEYES 2,548,815

ROTARY HOOK MECHANISM FOR SEWING MACHINES Filed June 10, 1949 2 Sheets-Sheet l ".4. P lm'n'r" IN V EN TOR.

5%4/ /43 A! fl k/56 x25 22% #13 Atwwey- April 10, 1951 c, PETSKEYES 2,548,815 I ROTARY HOOK MECHANISM FOR SEWING MACHINES Filed June 10, 1949 2 Sheets-Sheet 2 INVENTOR.

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Patented Apr. 10, 1951 ROTARY HOOK MECHANISM FOR SEWING MACHINES Charles H. Petskeyes, Davenport, Iowa, assignor to Gellman Manufacturing Company, Rock Island, 111., a corporation of Illinois Application June 10, 1949, Serial No. 98,311

6 Claims. 1

This invention relates to rotary hook mechanism for sewing machines. More particularly the invention has to do With a simplified construction for associating a bobbin case with the rotary hook, this being accomplished in a manner such as will eliminate clashing between the bobbin case and the rotary hook, the contemplated construction having a predetermined tolerance or clearance between the bobbin case and the hook such as will eliminate interference of the rotary hook with respect to the bobbin case by reason of the admission between the bobbin case and the rotary hook of foreign matter such as the lint from the thread.

In the operation of sewing machines there is always present a certain amount of lint from the thread. A certain amount of this lint between operating parts of the machine finds its way between the bobbin and the rotary hook. The constant accumulation of this lint will eventually interfere with the proper operation of the hook requiring the bobbin and rotary hook to be frequently disassembled to permit removal of the accumulated lint, this being particularly so where the relation between the bobbin case and the rotary case is of precision construction allowing no tolerance or clearance between the operating parts of the assembly.

Not only is it an object of my invention to provide a simplified construction to prevent clashing between the bobbin case and the hook, but it is also an equally important object of the invention to arrange the bobbin case with respect to the rotary hook in a manner such as will eliminate in a large measure interference of the rotary hook with respect to the bobbin case caused by the accumulation of lint or pieces of thread. In accomplishing this latter object, I dispense with the necessity of providing the usual thread cutters in the trackway of the hook.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:

Fig. 1 is a top plan view of the hook and bobbin case in assembled relation with respect to each other;

Fig. 2 is a bottom plan view of the same;

Fig. 3 is a sectional detail view taken substantially on line 33 of Fig. l;

Fig. 4 is a sectional detail view taken substantially on line 4-4 of Fig. 1;

Fig. 5 is a side elevational view of the same taken substantially on line 5-5 of Fig. 1;

Fig. 6 is an exploded view illustrating the several parts comprising the invention;

Fig. 7 is a plan view of the hook with the bobbin case removed;

Fig. 8 is a'plan view similar to Fig. 7, but illustrating a modified form of construction; and

Fig. 9 is a perspective view of the track ring embodied in the form of construction shown in Fig. 8.

I prefer to accomplish the several objects ofmy invention by the preferred forms of construction shown in the accompanying drawing. In this connection, the rotary hook is indicated at It]. In the bottom wall thereof is a centrally located opening II which receives the hook operating shaft (not shown) of the sewing machine. This hook provides side walls I2 having a relatively flat top surface I3. This side wall I2 provides a housing groove M.

The bobbin case is indicated at I5. This bobbin case provides a laterally extending flange I6, the peripheral edge ll of which extends into the groove I 4 and is retained therein by a gib ring I3 of relatively fiat formation and yieldably held in engagement with the top edge l3 of the wall R2 of the hook II]. This is accomplished by providing in the gib ring I8 perforations I9 providing seats for tapered edges 20 of connecting pins 2| projected through the perforations I9 and through the openings 22 formed in the side walls I2.

A spring plate 24 provides acentral hub 25 from which extend in opposite directions with respect to each other the arms 26. These arms 26 are perforated as at 21 and through these perforations 21 extend the ends of the pins 2|. The ends of the pins 2I which project through the perforations 21 are each provided with a transverse opening 28 to receive the angled end portions 29 of a connecting wire 30 whereby to complete the yieldable connection between the gib ring [8 and the hook I 0.

The plate 24 is normally buckled in the form,

shown in Figs. 3 and 6 to bear the arms 26 against the angled end portions 29 of the connecting wire 30 and is of a degree of resiliency which, while efiectively yieldably holding the gib ring flatly in contact with the top edge I3 of the hook I0,

may be pressed back upon the bottom wall of the hook to facilitate removal of the wire 30 with I5 provides a tracking groove 3! formed in the.

underside 32 thereof. Positioned against the inside surface 33 of the wall I2 is a track ring 34, the top edge of which extends into the groove M.

In the form shown in Figs. 1 to 6 inclusive, this track ring 34 is of split formation, the ends 35 of which are spaced from each other and when in assembled position in the hook are disposed on opposite sides of the hook 36 and thread guide 31. The outer wall 38 of the flange it provided by the formation of the groove 3% therein, normally rides on the bottom wall 39 of the groove M, the top edge 40 of the track ring being slightly spaced from the flange 16. As shown in Figs. 3 and 4 particularly, a clearance is provided between the outer wall 38 and the outer side surface of the track 34. Likewise, a clearance is provided between the wall 38 and the adjacent wall 4| of the wall i2. The clearance between the track 34 and the wall 38 is less than the clearance between the walls 38 and 4|. Should the hook by reason of centrifugal force or by other mechanical agencies be caused to shift laterally with respect to its central axis, clashing of the flange l5 against the wall 12 of the hook will be prevented by the engagement of the wall 38 with the track ring 34 and as there is a clearance between the gib ring !8 and the flange id, no clashing between these parts can take place.

Should thread or lint from the material being worked upon, find its way into the spaces provided by the several clearances hereinbefore referred to, such thread or lint will not be accumulated in such clearances so as to interfere with the rotation of the hook it but will be effectively worked out of the clearances without in any way retarding the rotation of such hook. The gib ring l8, being yieldably connected to the hook, will be permitted by the spring plate 24 to yield a suflicient distance to free any thread or lint.

By the construction herein set forth, it is apparent that my improved hook and bobbin case assembly is substantially non-clogging and nonclashing. The tracking ring 34 is connected to the hook by means of suitable rivets 42. It is preferably formed of such material as will best serve the purpose.

In the modified form of construction shown in Figs. 8 and 9, the track ring '34 is formed in one piece and likewise adapted to be secured in place by suitable rivets. In making this track ring 34 in one piece, the top edge 35' tapers a predetermined degree to provide'a narrow section 36' adapted to be disposed adjacent the hook 31 and thread guide 38'. The hook I8 is otherwise constructed in the same manner as that shown in Figs. 1 to '7 inclusive.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

l. For a, combination comprising a rotary hook having side walls providing adjacent the top edge thereof a groove, a bobbin case having a flange projecting into said groove and sai'd'flange providing in its undersurface a groove, a *gib ring for retaining said flange in the groove "of the rotary-hook, and a tracking Fmember carried by 4 the hook and having an edge portion engaging in the groove formed in the underside of said flange, said flange being spaced from the adjacent side walls of the groove in said hook and the top edge of said tracking member being normally spaced from the walls of the groove of said flange so that upon lateral shifting movement between said bobbin case and said hook said tracking member will restrain said flange from contacting said side walls of the groove of said hook.

2. For a combination comprising a rotary hook having side walls providing adjacent the top edge thereof a groove, a bobbin case having a flange projecting into said groove and said flange providing in its undersurface a groove, a gib ring for retaining said flange in the groove of the rotary hook, and a tracking member carried by the hook and having an edge portion engaging in the groove formed in the underside of said flange, there being a clearance between the flange and the side walls of the groove of said hook and between said flange and the said gib ring and between the top edge of said tracking member and the groove of said flange.

3. For a combination comprising a rotary hook having side walls providing adjacent the top edge thereof a groove, a bobbin case having a flange projecting into said groove and said flange providing in its undersurface a groove, a gib ring for retaining said flange in the groove of the rotary hook, and a tracking member carried by the hook and having an edge portion engaging in the groove formed in the underside of said flange, said flange being spaced from the adjacent side walls of the groove in said hook and the top edge of said tracking member being normally spaced from the walls of the groove of said flange so that upon lateral shifting movement between said bobbin case and said hook said tracking member will restrain said flange from contacting said side Walls of the groove of said hook, and means for yieldably connecting the gib ring to the hook.

4. For a combination comprising a rotary hook having side walls providing'adjacent the top edge thereof a groove, a bobbin "case having a flange projecting into said groove and said flange providing in its undersurfac'e a groove, a gib ring for retaining said flange in the groove of the rotary hook, a tracking member carried by the hook and having an edge portion engaging in the groove formed in the underside of said flange, there being a clearance between'the flange and the side walls of the groove'of said hook and between said flange and the said gib ring and between the top edge of said tracking member and the groove of said flange, and means for yieldably connecting the gib ring to the hook.

5. For a combination comprising a hook member having a side wall providing an internal groove, a bobbin case having a flange projecting into the groove and having riding contact with the bottom wall of said groove, said flange providing in its underside a groove, anda ring provided by said hook member and having an edge portion projecting into the groove of said flange, there being a clearance between said flange and the side wall of the groove of the hook member and a clearance between said top edge of said ring and the groove in said flange.

6. For a combinationcomprising a hook member having a. side wall providing an internal groove, a bobbin case having a flange projecting 5 into the groove and having riding contact with the bottom wall of said groove, said flange providing in its underside a groove, a ring provided by said hook member and having an edge portion projecting into the groove of said flange, there being a clearance between said flange and the side wall of the groove of the hook member and a clearance between said top edge of said ring and the groove in said flange, and means for yieldably retaining said flange in the groove of saidhook member and for retaining the edge of said ring in the groove of saidflange.

CHARLES PETSKEYES.

The following references file of this patent:

6 REFERENCES CITED are of'record in the UNITED STATES PATENTS Number Number Germany Mar. 17, 1930

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