US2875716A - Feed regulating mechanisms for sewing machines - Google Patents

Description

March 3, 1959 B P. P'lNKvoss 2,875,716

FEED REGULATING MECHNSMS FOR SEWING MACHINES Filed July 27, 1955 2 Sheets-Sheet 1 45 72 l` 7o q; l gay 50 i 'flo 2 i i l 11h/h I 4 I5 22 @j 2|v I' 'V --24 I8 o I4 Y f 23 I l INVENTR Bertha/dj? Pinkvoss7 Deceased v Agnes PnkvOSs, Execufrx WITNESS March 3, 1959 BJP. PINKvoss 2,875,716

FEED REGULATING MECHANISMS FOR SEWING MACHINES 2 Sheets-Sheet 2 Filed July 27, 1955 INVENTR Bertha/d l? Pin/rvoss, Deceased Agnes Pinkvoss, Execufrix WITNESS BY W AQJU w 7 g 7 ATT0RNE'V United States -Patent YO FEED REGULATING MECHANISMS FOR SEWING MACHINES Berthold I. Pinkvoss, deceased, late of Stratford, Conn.,

by Agnes Pinkvoss, cxecutrix, Stratford, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application July 27, 1955, Serial No. 524,774

1 Claim. (Cl. 112211) lnism for readily and conveniently varying the diameter `of a pulley which is arranged to actuate a belt driven top roller feed member of a sewing machine.

With the above and other objects and advantages in view as will hereinafter appear, this invention comprises the devices, combinations, and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

Fig. 1 is a vertical cross sectional view of a sewing machine having the feed regulating mechanism of this invention applied thereto.

Fig. 2 is an enlarged cross sectional view of the variable diameter pulley mechanism taken substantially along line 2-2 of Fig. 1.

Fig. 3 represents an exploded perspective view of the variable diameter pulley mechanism of Figs. l and 2.

Referring to the drawings, the invention is illustrated in Fig. 1 as applied to a sewing machine having a work supporting post 11 mounted upon a machine bed 12 which also carries a pedestal 13 surmounted by a bracket arm 14 which terminates in a sewing head 15 overlying the post 11. The sewing machine illustrated in Fig. l is constructed and arranged substantially in accordance with U. S. patent of Pinkvoss, No. 2,678,010, May 1l, 1954, to which reference may be had for a general description thereof. The present invention concerns a regulating mechanism for the work feeding instrumentalities of the sewing machine which comprise a lower feed wheel 16 journaled in the work supporting post 11, and a driven top roller feed member 17 journaled in a bracket 18 carried by the conventional presser bar (not shown) of the sewing machine.

A main drive shaft 20 journaled in the backet arm carries a hand wheel pulley 21 and is tted with conventional driving connections in the sewing head for reciprocating a needle bar 22 carrying a needle 23. By means of a clip belt 24 rotary motion is transmitted from the main drive shaft 20 to a bed shaft 25 which is geared, as described in detail in the above referenced patent, to a hook shaft 26 journaled vertically in the post 11 and carrying at its upper extremity a rotary hook 27 adapted to cooperate with the needle 23 in the formation of lock stitches.

The feed wheel 16 is carried in the post 11 by means of a vertically adjustable bracket 30 and has formed as a part thereof bevel-gear teeth 31 disposed in mesh with a pinion 32 fast on the upper part 33 of a feed shaft Aice journaled vertically in a sleeve bushing 34 in the post 11. A universal connection 35 is provided between the upper part 33 and a lower portion 36 of the feed shaft. A one-way clutch device 37 of the type disclosed in the U. S. patent of Hacklander, No. 2,277,971, is carried by the lower portion 36 of the feed shaft. This clutch 37 is adapted to be oscillated by means of an actuating arm 38 connected to a pitman 39 which embraces an eccentric (not shown) fast on the bed shaft 25. Intermittent rotary motion in one direction is transmitted to the feed wheel 16 by actuation of the clutch 37.

The top roller feed member 17 is drivingly connected with the feed shaft so as to insure synchronism of feed wheel and top roller movements. The driving connections include a pulley il fast on the lower poition 36 of the feed shaft, a belt ft2 engaging the pulley 41 with a pulley 43 fast on the lower extremity of a shaft 44 which is journaled vertically through the pedestal 13 and the bracket arm 1li, and a beit 45 which is arranged to engage the top roller 17 and is directed over a pair of idler rollers i6 to a pulley indicated generally as 47 carried at the upper extremity ofthe vertical shaft d4.

Although the belts Li2 and 45 and the vertical shaft 44 serve to synchronize movements of the feed wheel and top roller, proper control of the work fabrics gives rise to a need for control of the relative extent or magnitude of movement of the work feeding wheels 16 and 17. It is also pointed out that `the relative extent of work feeding motion between the feed members has no single optimum value but changes as the nature of the work changes. Thus, there is no one relationship to which the parts could be adjusted or designed to provide which would be satisfactory under all conditions.

In this invention, control of the extent of work feeding motion of the top roller 17 relative to the feed wheel 16 is obtainable by means of the pulley 47 on the vertical shaft 44. The pulley d'7 is constructed so as to provide a compact arrangement of parts, disposed so as to be readily accessible to the machine operator and arranged to provide a micrometer adjustment of the diameter of the belt-engaging portion thereof so that the extent of feed motion of the top roller may be regulated with respect to that of the feed wheel. Regardless of the character of work being stitched, therefore, the present invention provides convenient regulation effective to insure that each of the plies being stitched will be fed at precisely the required rate.

Referring to Figs. 2 and 3, the variable diameter pulley of this invention is carried directly upon the upper extremity of the vertical shaft 11i-i and is disposed to surmount a bearing bracket 5d in which the upper extremity of the shaft 44 is journaled. Fast on the .shaft dst, as by set screws 51--5l, and contiguous with the bearing bracket 5d is a collar 52 formed with a counterbore 53. Screw threads 54 are formed on the upper extremity of the shaft 44 upon which a diameter regulating member 5S is threadedly engaged. The diameter regulating member 55 is formed with a conically shaped lower portion 56 provided with four evenly spaced slots 57-57 each extending lengthwise of the regulating member. Above the conical portion 56, the member S5 is formed with external threads 5S and with diametrically opposed screw driver slots SQL-r9. Endwise movement of the member 55 is limited by the bottom of the counterhore in a downward direction and by a locking screw 6ft threaded into the shaft 44 at the upper end thereof.

The belt engaging portion of the pulley comprises a composite sheave made up of an assembly of four sector shaped pulley segments 61 arranged in the form of an annular ring. The inner surface 62 of each of the segments is tapered to match the angle of the conical portion 56 at the member 55. The outside surface of each of 'geref/1e accommodating portion 63 and a projecting inclined portion 64, the portions being separated by an annular undercut 65 which provides a seat into which an annular spring clip 66 is disposed. The clip 66 serves yieldingly to urge the segments against the conical portion 56 of the diameter regulating member. Each of the segments is, in addition, formed with an aperture 6'7 adapted to receive a pin 68 of which the head portion is slidably arranged in one of the slots 57 of the regulating member so as to key the segments in place and prevent turning of the segments relatively to the regulating member. An annular locking ring 69 encircles and engages the projecting inclined portions 64 of the segments and is retained securely in place by means of a lock nut '70 which engages the external threads 58 of the regulating member. VThe locking ring 69 serves to clamp the segments, the diameter regulating member and the shaft together for rotation as a unit.

The bracket arm 14 of the sewing machine is tted with a conventional top cover plate '71 formed with an aperture '72 through which protrude the diameter regulatving member 55 and the lock nut 70. The major portion of the variable diameter pulley, therefore, is housed within the bracket arm and only those portions to which access is required for effecting the necessary adjustments are exposed for ready accessibility to the sewing machine operator.

In operation, the belt accommodating segments 61 are locked in position between the collar 52 and the locking ring 69. The position of the segments against the regulating member 55 determines the diameter of the belt ac commodating surfaces 63. of the pulley, the lock nut 70 must be loosened to free the segments 61, the diameter regulating member 55 may then be turned. If the member 55 is turned countern In order to vary the diameter y Y' 'clockwise and moved upwardly on the shaft 44, the spring w v clip 66 will cause the segments 61 to shift inwardly thus yielding force of the annular spring clip 66 and will thus increase the pulley diameter. When the proper setting is reached, tightening of the lock nut 70 will x the parts in the proper position against accidental movement.

The construction of this inventiom therefore, provides a feed regulator which is readily accessible and convenient to adjust by which a micrometer adjustment may be obtained of the relative extent of feed between opposed feed wheels. Regardless of the type of work being stitched, therefore, the sewing machine may be readied quickly and easily to advance both the upper and the lower plies at precisely the required rate past the stitch forming instrumentalities.

Having thus described the nature of the invention, what is claimed herein is:

In a sewing machine having a hollow frame including a work support associated with a bed, a standard rising from said bed, and a bracket arm carried by said standard and disposed to overhang said work support, a compound work feeding mechanism comprising a lower work feeding instrumentality carried by said work support, mech- 'anism actuated by said sewing machine for imparting intermittent work feeding motion to said lower work feeding instrumentality, an upper work feeding wheel carried by said bracket arm, a shaft journaled vertically in `said standard, positive driving connections between said work feeding instrumentality and the lower extremity of said shaft, a variable diameter pulley carried at the upper extremity of said shaft, a belt extending between said variable diameter pulley and said upper work feeding wheel, said variable diameter pulley including an angularly adjustable diameter regulating member and an angularly adjustable locking member for said regulating member, said sewing machine bracket arm being formed with an aperture disposed substantially in axial alignment with said shaft through which said regulating and said locking members are disposedito extend outside the sewing machine frame.

References Cited in the le of this patent UNITED STATES PATENTS 2,022,115 Howe Nov. 26, 1935 2,325,643 Weis Aug. 3; 1945 2,678,010 Pinkvoss May 11, 1954

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