US2749862A - Sewing machines - Google Patents

Description

June 12, 1956 A. N. HALE SEWING MACHINES 6 Sheets-Sheet 1 Filed May 12, 1951 INVENTOR @Qrthur JV Hale ATTORNEY WITNESS June 12, 1956 A, E 2,749,862

SEWING MACHINES Filed May 12. 1951 6 Sheets-Sheet 3 INVENTOR cflrzfhwr JVT Hale ATTORNEY June 12, 1956 A. N. HALE SEWING MACHINES 6 Sheets-Sheet 4 Filed May 12 INVENTOR vZrthu/r JV Hale ATTORNEY June 12, 1956 A. N. HALE 2,749,862

SEWING MACHINES Filed May 12, 1951 6 Sheets-Sheet 5 INVENTOR cflrtlzur JV Hale WITNESS June 12, 1956 A. N. HALE SEWING MACHINES 6 Sheets-Sheet 6 Filed May 12 51 87 l J k INVENTOR flrthwr Jl. Hale WWW WITNESS ATTORNEY 3 Claims. (Cl. 112-220) This invention relates to sewing machines, more particularly of the chain-stitch type, and has for an object I to provide an organized sewing machine of the type in question having improved characteristics enabling .itto be commerciallly operated at speeds of the order exceedi-ng 5000 stitches per minute, without undue wearand tear on the parts.

Another object of the present invention is to provide a machine of the above indicated type in which all the operating mechanisms are designed so that they can be readily assembled and disassembled with the aid of simple hand tools.

Afurther object of the present invention is 'to provide a machine of the class described with operating mechanisms which are extremely light in weight so that the machine'can be operated at high speeds with a minimum of vibration.

A still further object of the present invention is to provide a sewing machine having operating mechanisms designed to be produced as sub-assemblies capable of being readily assembled into a machined frame with the aid of only a simple screw-driver.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, cornbinations and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

Referring to the drawings,

Fig. 1 is a front side elevation of a sewing machine embodying the invention.

Fig. 2 is a vertical sectional view taken longitudinally of the machine frame, showing the two-part construction of the mainor bed-shaft and the manner in which the arm-shaft is operatively connected to the bed-shaft- Fig. 3 is an enlarged top plan view of the lower four I motion feeding mechanism, with a portion of the feedlength adjusting means in section.

Fig. 4 is a rear elevation of the bracket-arm and head of the machine, a portion of the bracket-arm being sectioned to illustrate the preferred method of supporting the inner end of the resser-foot lifter rod.

Fig. 5 is a transverse vertical section taken substantially along the line 55, Fig. 1.

Fig. 6 is a left end elevation.

Fig. 7 is a left end elevation with the face-plate removed from the head and the cloth-plate, drip-pan and one of the resilient mountings in section.

Fig. 8 is an enlarged sectional view taken substantially along the line 3-8, Fig. 7.

. Fig. 9 is a vertical sectional view taken transversely of 43 the auxiliary section 39 of the cloth-plate.

2,7493% Patented June 12, 1956 ing mechanism with the feed-advance and feed-lift eccentrics in section.

Fig. 11 is a disassembled view of the two-part bed-shaft, showing the manner in which the right hand part of the bed-shaft is secured in its ball-bearing mount as a sub-assembly.

Fig. 12 is a right hand face view of the larger section of the bed-shaft shown in Fig. 11.

Fig. 13 is a left hand face view of the smaller section of the bed-shaft shown in Fig. 11.

Fig. 14 is atop plan view of the sewing machine, illustrating the path of travel of the sewing thread through the tension device, thread-controller and nipper.

Fig. 15 is a horizontal section taken lengthwise of the bracket-arm, showing in detail the ball-bearing mounts for the arm-shaft and the way in which the arm-shaft is assembled in the bracket-arm.

Fig. 16 is a vertical section taken substantially along the line 1616, Fig. 14.

Fig. '17 is a vertical section taken substantially along the line 17--'17, Fig. 14.

Fig. 18 is a horizontal section taken substantially along theline 18-48, Fig. 17.

Fig. 19 is an enlarged vertical sectional view of the thread nipper device shown in Fig. 2.

The detailed description which follows is broken down into sections and each individual mechanism of the sewing machine will be discussed under the appropriate subtitle.

M (whine-frame The hollow machine-frame, which is preferably cast in one piece, comprises a bed 20 from one end of which rises a standard 21 of an overhanging bracket-arm 22 terminating in a head 23.

The "bed 20 is transversely formed with depending end- walls 24 and 25 providing bearing supports for the opposite ends of a mainor bed-shaft 26 later described. Intermediate the end- walls 24 and 25 is a depending transverse partition 27 providing a third bearing of the bed-shaft 26. Spanning the space between the end-wall 24 and the partition 27 is a horizontal wall 28 (Figs. 2 and 5) affording the top of a lubrication compartment 29 closed at its bottom by a removable plate 30. The lubrication compartment 29 is in communication with the hollow 31 of the standard 21, whereby the oil-laden atmosphere created in the compartment 29 may lubricate the operating connections in the bed and standard. Ad-

jacent the right-hand end of the bracket-arm 22 there is provided a partition 32, Figs. 2, 5 and 15, separating the hollow of the bracket-arm 22 from the hollow of the standard 21 and supporting the rear bearing for an armsliaft 33. The front bearing for the arm-shaft 33 is mounted in a partial partition 34, Figs. 2 and 15, formed within the bracket-arm 22 at the point where it merges into the head 23 of the machine. A sheet-metal faceplate 35 closes the head against ingress of dirt and lint and confines any spent lubricant within the head. To facilitate assembly of the mechanism within the bracketarm 22 an access opening 36 is formed in the upper end of the standard and a detachable cover-plate 37 is provided to close said access opening.

' Mounted on the bed 20 in a fiat two-piece cloth- plate 38, 39 of which the main section 38 is fixed, as by screws 40, Fig. 2, to the bed and carries the usual throat-plate 41. The main section 38 adjacent its rear edge has projecting from it an extension 42, Figs. 1, 2 and 6, on which is pivoted for horizontal movement about a pivot-stud As shown in Fig. 1, the two sections 38 and 39 of the cloth-plate abut each other along the line 44 when in their normal closed position. The pivotal support for the auxiliary section 39 permits its to be swung to an open position better to expose the lower stitch-forming and feeding devices. Soldered or otherwise secured to the under surface of the auxiliary section 39 of the cloth-plate is a looper guard 45 which normally encloses the looper later to be described.

The entire machine is preferably yieldingly supported on four resilient cushions 46, Fig. 7, housed at their upper ends in apertured pads 47 cast integral with the machinebed 20. Each of the resilient cushions 46 is bored, as at 48, to receive a locating button 49 brazed or otherwise secured to a sheet-metal box-like drip-pan 50. Each of the locating buttons 49 is apertured to accommodate a wood-screw 51 which is adapted to be screwed into a conventional table structure 52. It will be appreciated that the locating buttons 49 position the machine within the drip-pan 50 which is attached to the table-top 52, and that the machine can be readily removed from the drippan by simply lifting the machine and sliding the resilient cushions 46 off the locating buttons 49.

Main-shaft construction The main-shaft of the machine is journaled for rotation in the bed 20. The shaft, which is indicated generally by the reference 26, is best seen in Figs. 2, '11, 12 and 13, and includes a front section 53 and a relatively shorter rear section 54; the proximate ends of the sections 53 and 54 comprising an articulated crank having separable components. The front section 53 is journaled in the plain bushed bearings 55 and 56 disposed in the partitions 24 and 27, respectively, of the bed. The shaft section 53 is tubular, having a longitudinal bore, as at 57, for a major portion of its length, and adjacent its front end is formed with a feed-advance eccentric 58 and a feed-lift eccentric 59.

Mounted in a hole 60 drilled axially in the front end of the shaft-section 53 is a conventional form of wingtype looper 61. Brazed or otherwise secured on the reduced rear end portion of the shaft section 53 is a counterbalanced disk-shaped crank-cheek 62 forming one component of the articulated crank; the crank-check being formed in its end face with a radially extending notch 63 and having its periphery 64 cut eccentrically of the axis of rotation of the shaft-section 53, thereby to provide an eccentric for actuating a thread-nipper later to be described.

. Projecting into the radially extending notch 63 in the crank-cheek 62 is the reduced outer end of a crank-pin 65 brazed or otherwise secured in a second counterbalanced'disk-like crank-cheek 66 suitably fastened on the rear shaft-section 54. As will be seen in Fig. 2, the rear shaft-section 54 is journaled in ball- bearings 67 and 68 mounted in spaced relation in a sleeve 69 adapted to be replaceably mounted in a shaft assembly aperture 70 formed in the wall 25 of the bed. Mounted on the exposed end of the rear shaft-section is a combination handwheel and belt-pulley 71. For assembly purposes, the aperture 70 is sized to exceed slightly the diameter of the crank-cheek 66 so that the crank-cheek 66 with its crankpin 65, shaft 54, ball- bearings 67 and 68, sleeve 69 and hand-wheel 71 can be assembled as a unit outside the machine and inserted through the aperture 70. A set-screw 72 locks the unit in place and a conventional resilient ring-gasket 73 prevents escape of the oil in the lubrication compartment 29-31 outwardly along the surface of the aperture 70.

From the above description, it will be understood that the main-shaft 26 consists of two individually complete units 53 and 54, of which the axes are collinear and the units can be assembled into the machine-frame by first inserting section 53 followed by section 54 through the aperture 70 in the wall 25 of the bed 20, the two sections being suitably interconnected by the crank-pin 65 entering the notch 63. Moreover, it will be appreciated that the main-shaft 26 is held in its proper position in the machine-frame by only one or more set screws 72.

With a view toward balancing, it will be noted in Fig. 2 that the counterweight portion of cheek 66 is disposed diametrically opposite the crank-pin 65 and in substantial alinement with the connecting link journaled on said crank-pin, whereby dynamic balancing is obtained in the rear shaft-section 54 resulting in no unbalanced forcesbeing transmitted to the front shaft-section 53. Also it will be noted that the belt pull on the hand-wheel 71 is in line with the ball-bearing 68 so that the belt tension will be not create a cantilever effect on the rear shaftsection 54.

Needle-bar mechanism The looper 61 is complemental, in the formation of single-thread chain-stiches, to a thread-carrying needle 73 carried in the lower end of an endwise reciprocatory needle-bar 74 journaled in bearing bushings 75 and 76 (Fig. 2) fixed in the machine-head 23. The mechanism for reciprocating the needle-bar 74 is best shown in Figs. 2, 5, 7 and 15, and comprises a needle-bar stud 77 clamped by screw 78 (Fig. 7) on the needle-bar 74. The needle 'bar stud 77 is embraced by the lower end of a needle bar actuating link 79 (Fig. 2) which is connected at its upper end to a rock-arm 80 clamped by screws 81 on the armshaft 33. The arm-shaft 33, at the head end of the machine, is journaled in a ball-bearing 83 (Fig. 15) and, at the standard end of the machine, is journaled in a ballbearing 83. Rocking movements are imparted to the arm-shaft 33 by means of a rock-arm 84 preferably pinned or otherwise fastened on the standard end of the armshaft 33; the rock-arm 84 having connected to its free end the upper end of a driving link 85 embracing at its lower end the crank-pin 65 on the rotary bed-shaft 26. As will be clearly seen in Figs. 2, 5 and 15, the upper end of the driving link 85 is constrained on the free end of the, rock-arm 84 against sliding off the same by being confiined between a machined face 86 provided on the partition 32 and the rock-arm 84.

From the above description, it will be appreciated that the rock-arm 84 is pinned or otherwise fastened on the arm-shaft or rock-shaft 33 and that the rock-arm 80 is clamped on the rock-shaft 33. To properly secure the arm-shaft 33 against endwise movement in its ball- bearings 82 and 83, there is threaded on the front end of the arm-shaft 33 a nut 87 (Fig. 15) which functions to draw the arm-shaft 33 lengthwise of the bracket-arm 22 until excess play between the hub of the rock-arm 84 and the inner race of the ball bearing 83 is eliminated. The nut 87 is frictionally locked on the arm-shaft 33 by a wedgescrew 88 located in the slotted outer end of the arm-shaft, the wedge-screw 88 being threaded into an insert 89 pinned or otherwise secured within the bore of the armshaft 33. Tightening of the wedge-screw 88 expands the slotted end of the arm-shaft 33 and precludes accidental loosening of the nut 87.

In Fig. 15 it will be seen that the bearings 82 and 83 are alined respectively with the connecting links 79 and 85, the advantage of this arrangement being that the armshaft 33 is not subjected to any bending and that its forces are torsional only.

Presser mechanism The presser mechanism, which forms the subject of a divisional application Serial No, 301,272, filed July 28, 1952, is best illustrated in Figs. 4, 6, 7 and 8, and in its preferred form comprises a suitable presser-foot 90 carried on the lower end of a vertically disposed presser-bar 91 endwise slidably mounted in the head 23. Surrounding the upper portion of the presser-bar 91 is a coil-spring 92 which biases the presser-foot 90 into engagement with the Work by reacting at its upper end against a cap-screw 93 adjustably threaded in the machine-head 23 and mm trally bored to provide the upper bearing for the presserbar. 'At its, lower end the coil-spring 92 engages a presserfbar guiding and lifting bracket 94 :clamped by set screw 95 in selected position-on the presses-bar 91. Ascshown in Fig. 8, the bracket 94.gui.ies or, in other words-prevents the 'presser-bar 91 from turning in its bearings by being formed with a guide-lug 95 which rides in a guide- Way 96 milled in the machine head 23. Projecting rearwardly from the bracket 94 is a lifting extension 97 disposed vertically above the usual pivotally mounted handlifting cam-lever 98. Manual raising of the hand-lifting .cam-lever'98 will cause it to engage the lifting extension 97 and thereby raise the resser-foot 96 against the action of the coil-spring 92. Lowering of the cam-lever 98 will permit the spring 92 to return the ;presser-foot 90 to its lowered work-engaging position.

.Means is provided for raising the resser-foot 90 by knee-shift or foot-treadle. This means comprises a lifting rock-arm 99 secured, as by brazing, to one end of a presser-lifting rock-shaft 100 located rearwardly of the bracket-arm 22 and journaled in spaced bearings 101 and 102 (Fig. 4) provided in the bracket-arm. The :free end of the lifting rock-arm 99 is offset or bent at right angles,

as at 1'93 (Figs. 7 and 8), torextend into a vertical open- ;bottom slot 1.04 formed in the liftingextension 97. scillation of the lifting rock-arm 99 will cause its offset end 193 to contact the liftingiextension 97 and thus elevate -tl1e presser-foot 90. The slot 194 is open at its bottom to permit the hand-lifting lever 90 to be manually raised to elevate the presser-foot without causing movement of the lifting rock-arm 99. The presser-lifting rock-shaft rschas secured on it by set-screw 105 (Fig. '4) a rearwardly extending actuating lever 106 suitably connected to a knee-shift or foot treadle not shown. Azspring 107 acting between the lever 106 and the bracket-arm .nortnally elevates the lever 1G6 and maintainsthe lifting rockarm 99 in engagement with a stop-pin 168 (Fig. 7).

As will be seen in Fig. 4, the bearing 102 for the presser-lifting rock-shaft 100 is preferably drilled directly into the bracket-arm wall and the inner end of the presserl-ift'in'g rock-shaft is retained :in this bearing hole by the fact that the lifting rock-arm 99 .(Fig. 8) is confined between the lifting extension 97 and a flat face or surface 149 machined on the end-face of the machine-head 23 in substantial parallelism with the proximate face of the lifting extension 97. As will be seen in Fig. 8, the guidelug 95 on the lifting bracket 94 maintains the presserbar91 against turning in its bearings and, at the same time, anchors the lifting extension 97 so that it confines the lifting rock-arm 99 and thereby prevents end'wise displacement of the rock-shaft 160.

Feeding mechanism To provide for advancing the work past :the stitching devices, the present machine is equipped with a lower fourrnotion feeding mechanism best shown in Figs. 3, 6, 7, 9 and 10. The feeding mechanism, which forms the subject of .a divisional application Serial No. 301,271, filed July .28, 1952, now Patent No. 2,672,112, dated March 16, 1954, preferably is designed as 'a .unit capable of being put together as a sub-assembly and applied to the machine in a simple and eflicient manner. To that end, the present feeding mechanism includes a feed-dog 110 clamped by a screw 11.1 for limited vertical adjustment on a feed-bar 112 carrying at its widened rear end api-vot rod 113 of which the opposite ends are journaled in the upstanding limbs 114 of a feed-rocker 115. The .feedrocker 115 is journaled for oscillatory movements on a fulcrum-stud 116 fixed by a set screw 117 in the machinebed 26.

Lifting movements are imparted to the feed-dog 110 by the feed-lift eccentric 59 preferably integral withthe exposed end of the mainor bed-shaft 26. The feed-lift eccentric is embraced by a block 118 having flanged oppositefaces engaged by the bifurcated end 119 of the feedbar 112. Rotation of the bed-shaft 26 will impart .to-the feed-bar 112 and consequently the feed-dog 110, oscillaused wherever possible.

tory vertical lmovem'ents about tthe longitudinal :axis of -tthe;pivot-rod 113, the oscillations being such as "to :raise and lower the feed-dog 116 into and out of engagement with the material through the usual feed-dog slots in the throat-plate 41.

Thefeed-advance and -return movements of the feeddqg 119 are derived :from the feed-advance eccentric '58 :also preferably-formed'integral with the bed-shaft 26. .As will be clearly seen in Fig. -l0,:th"e feed-advance eccentric :58 is embraced (by one end of a short pitman 1'20 connected at its oppositeend to a knuckleepin .121 of a pair .of tqggle-links'fl22 and .123. The upper end of the togglelink 122 is connected to a;pin 124 fixed in=thefeed=bar 112 near its rear end. The .lower end of the toggle-link 123 is freely journaled on a 'fulcrum-pin125 fixed in the lower end of an anchor-arm 1265 supported at its upper end on a rod 127 journaled in alined bearing holes provided 'in the end-wall 24 and the partition 27. From the above description, it will .be understoo'dtthat rotation of the feedadvance eccentric will result "in a substantially endwise movement of .the upper :end of the toggle-link -12 2;"this movement 0f the toggle-link being transmitted by the pin 124-10 the feed-bar 112. Proper relative timing bet-ween the feed-lift ieccentr-ic 59 and the "feed-advance eccentric v58 effects a four-motion travel of the feed-dog 110.

It will be appreciated that the knuckle joint 'of the toggle- links 122 and 123 is constrained to move in an :arc struck vabout the axis of the'fulcrum-pin 125, andthat .by manually swinging the fulcrum pin 125 about the axis of the anchor-arm supporting rod 127 the horizontal component of the resultant motion of knuckl'e-pin 123 40911138 changed. This results in'a change in the stitch- ,l'en'gth. To effect a shift in the position of the fulcrumpin 125, means :is provided beneath the cloth-plate 38 which can be operated in a manner such that its posiftion of adjustment can be :seen through a cut-out 1 28 (Fig. 7,) in the cloth=pla-te. This means comprises a thin sheet-metal link 129 (Fig. 10) apertured, as *at .130, to embrace the slightlyextended end or projection 131 of the fulcrum-pin 125. At its front end tfhe sheetmetal link 129 is apertured, as at 132, to receive a cylindrical :lug 133 extending outwardly from the endface of a thumb-disk 134 which iscsupported for turning ened to clamp the thumb-disk 134 against accidental turning. The hand-lever 137 is adjustably fastened to the stud by a cap-screw 138 which secures the handlever against the serrated end-face 139 of the stud 135. This permits adjustment of the shand lever 137 relative to the stud 135. It will be observed in Figs. 2 and 3 that the feeding mechanism in its entirety is located outside the lubrication compartment 29 and, in order to minimize the need for repeated hand oiling of the bear- "ings in the feeding mechanism, bushing 140 (Fig. 10)

preferably comprising oil impregnated sintered metal are Also, the bearing block 118 is preferably made of the same material as the bushings.

Contributing to the simplification of the feeding mechanism :is the manner in which the stitch-length adjusting link 129 is maintained operatively connected to the extended end 131 of the fulcrum pin 125 and the projection 133 on the thumb-disk 134. As will be seen in Figs. 3 and 10, the thumb-disk 134 is provided with a hub 141 and the anchor-arm 126 is milled to provide .afinished face 142, the depth of the face 142 and the thickness of the hub 141 being slightly greater than the thickness of the link 129. When assembled in the machine, the stitch-length adjustinglink 129 is confined at one end between the thumb-disk 134 andthe machined outer face 143 of the machine-bed end-wall24, and at its other end between the anchor-arm 126 and the outer Thread-controlling devices The needle-thread T is led from a source of supply through a thread guide 144 (Figs. 1, 4 and 14), then between the disks of a tension device 145 of the type substantially like that disclosed in the Chason Patent No. 1,862,658, issued June 14, 1932. From the tension device 145 the thread T passes through a thread-measuring or stitch-by-stitch pull-off device, indicated generally as 146, and thence between the disks of a thread-nipper 147 to a thread-guide 148, a take-up hole 149 in the needle-bar 74, a thread-check 150 and a thread-guide 151 -on the face-plate 34, and then to the eye of the needle The stitch-by-stitch pull-off device 146, which is disclosed in the accompanying drawings to permit a complete understanding of the present machine, forms the subject of a copending patent application Serial No. 225,990, filed May 12, 1951, now Patent No. 2,626,580,

.dated January 27, 1953, in. the name of Edward L.

Koenig, and the same will be hereinafter described only in sufficient detail to enable a clear understanding of its operation. As will be seen in Figs. 14, 15, 16, 17 and 18, the pull-off device comprises a normally stationary member 152 and a movable thread-engaging member 153 secured by a screw 154 to the oscillatory arm-shaft 33.

The movable thread-engaging member or pull-ofi arm 153 is periodically operated stitch-by-stitch so that its free end passes through and engages the needle-thread T spanning the space between two alined thread- eyes 155 and 156 formed in the spaced limbs 157 and 158 provided on the stationary member 152. The pull-off arm 153 in its advanced position, shown in dotted lines in Fig. 14, forms a bight in the needle-thread T, the excess thread forming the bight being pulled from the supply .through the tension device 145. To insure that all the thread forming the bight is obtained from the supply, the pull-off arm 153 is timed so that it operates on the needlethread T only while the nipper 147 is closed. To control the length of thread pulled from the supply, the stationary member 152 is supported so that it can be manually shifted relative to the free end of the pull-off arm 153 thus to change the effective stroke of the pull-off arm. To provide for shifting the stationary member 152, the said member is provided at one end with a pivot-pin .159 which projects into a hole drilled in the bracket- -arm 22. -152 is enlarged and apertured, as at 160, to receive .an adjusting eccentric 161 preferably integrally formed Intermediate its ends the stationary member on the lower end of aregulating knob 162 journaled for turning movement on a stud 163 threaded into the bracket-arm 22.. To.eliminate accidental turning of the regulating knob 162, there is provided a compression spring 164 operating between the head of the stud 163 and a flange on the regulating knob 162, whereby said knob is frictionally held in its selected position of adjustment. To facilitate the proper adjustment of the thread measuring device, there is clamped between the bracket-arm 22 and a shoulder on the stud 163 (Fig. 17)

a pointer .or indicator 165 which is disposed to cooperate with suitable indicia scribed in'the skirt portion of the regulating knob 162. From the above description, it

will be understood that turning of the regulating knob 162 will turn the eccentric 161 and thus swing the stationary member 152 about its pivot-pin 159 so that the thread-guides and 156 are moved relative to the free end of the pull-off arm 153. This relative movement results in a change in the effective stroke of the pulloff arm 153.

As mentioned above, the pull-off device is effective to draw thread from the supply when the nipper 147 is opened. The nipper, best shown in Fig. 2, comprises a pair of thread-engaging disks 166 loosely mounted on a headed stud 167 threaded at its lower end into a plunger 168 which is slidable in a bore in an externally threaded body member 169 adjustably secured in the bracket-arm 22. Disposed in the bore of the body-member 169 is a coil-spring 179 which functions to normally yieldingly close the thread-engaging disks 166 into thread-gripping relation. Means are provided to intermittently open the thread-engaging disks 166 so that the thread T can be fed to the needle 73. This means preferably comprises a release-rod 171 journaled for endwise sliding movement in an upper bearing bushing 172 fixed in the bracketarm 22 and in a lower bearing lug 173 cast integral with the standard 21. At its lower end the release-rod 171 has pressed on it or otherwise fastened to it a sleeve 174 to which is secured a cam-follower button 175 adapted to ride on the periphery 64 of the crank-cheek 62, which periphery 64 is formed as an eccentric providing an automatic nipper-opening cam. In order to maintain the nipper-release-rod button 175 in contact with the cam 64 a coil-spring 177 is provided. The upper end of the coil-spring 177 bears against the fixed bearing bushing 172 and its lower end bears against the end-wise slidable sleeve'174. It will be understood that the time when the nipper 147 is opened can be shortened or lengthened by screwing the body-member 169 in or out of the bracket-arm 22. This shifts the nipper assembly supported by the body-member 169 relative to the upper end of the release-rod 171 and by so doing affects the time when the nipper opens and closes.

The remaining elements through which the needlethread T passes in its travel to the eye in the needle are conventional and require no further description.

Lubrication With the exception of the feeding mechanism, which is fitted with oil impregnated sintered metal bushings and therefor requires very little lubrication, the mechanisms of the machine are automatically lubricated by means of a splash system. The lubrication system of the present machine forms the subject of a divisional appplication Serial No. 301,273, now Patent No. 2,652,799, dated September 22, 1953, filed July 28, 1952. As previously described, the machine-bed 20 is formed with a lubrication compartment 29 closed at its bottom by a removable plate 30 and adapted to be filled with suitable lubricant to a level indicated on a transparent oi-level indicator 178 secured in an inclined front wall-portion of the bed 20. Beneath the standard 21 of the machine the lubrication compartment 29 is in communication with the hollow 31 of the standard, the hollow at its upper end being closed by the transverse partition 32.

Oil collected in the bottom of the lubrication compartment is adapted to be splashed about within the compartment 29 and the hollow 31 by a splash-finger 179 (Figs. 2 and 5) depending from the lower end of the armshaft driving link 85. The crank-pin driving the link 85 is lubricated by means of an oil-conducting ring 180 (Fig. 2) pressed on the outer race of the ball-bearing 67 and formed with a reduced annular projection 181 shaped to collect oil deposited on the oil-conducting ring and deliver it within an annular recess 182 formed in the end face of the crank-cheek 66. The annular recess 182 has communicating with it a duct 183 disposed lengthwise of the crank-pin 65, which duct 183 opens into the periphery of the crank-pin 65 and thereby leads oil to this surface. The ball bearings 67 and 68 are of the sealed type and therefore no oil escapes through these bearings to contaminate the hand-wheel 71. It will be appreciated that the oil-collecting ring 180 functions as an oil guard and augments the sealed bearings 67 and 68 in precluding the escape of oil to the hand-wheel 71.

The arm-shaft 33 and its associated connections are lubricated by oil collected by a wick 184 (Figs. 2 and 15) located in the central bore 185 of the arm-shaft, the wick having its right hand end exposed to absorb oil splashed within the hollow 31 of the standard 21. At the standard end of the arm-shaft 33, the central bore 185 thereof is connected by a port 186 to a duct 1187 running lengthwise of the rock-arm 4 and opening at the outer end of the rock-arm into the bearing surface between the rock-arm and the driving link 85. Thus, oil absorbed by the wick is conducted by the port 186 and duct 187 to the armshaft driving connection.

At the head end of the arm-shaft 33, the central bore 185 thereof is connected by a port 188 to a duct 189 running lengthwise of the needle-bar actuating rock-arm 8i) and opening at its outer end on the bearing surface between the rock-arm 86 and the needle-bar actuating link 79. As will be seen in Fig. 2, excess oil delivered to the upper end of the needle-bar actuating link '79 is conducted downwardly through a central duct 1% in the link 79 to its lower bearing. From the above, it will be understood that the exposed end of the wick 184 absorbs oil from the oil-laden atmosphere in the hollow 31 of the standard 21 and then, through the ports E86 and 188 and ducts 137 and 189, delivers it to the bearing points requiring lubrication.

As previously mentioned, the level of the oil in the lubrication compartment 29 is visible through the transparent plug 178 (Fig. which plug has oil-level limit lines 191 cut in its inner face. These oil-level limit lines cross an oil-receiving hole 192 which is provided transversely of the inner face of the plug 178 and closed by an end-plate 1%, thereby to provide an oil-receiving hole open at its upper and lower ends and into which the oil in the compartment 29 may rise to seek its own level. Oil in the compartment 29 may be replenished through an o-il-illing hole H4 formed in the horizontal top wall 28 of the compartment 29. Protruding from the upper surface of the top-wall 28 are two ridges 194 arranged at opposite sides and parallel to the front shaft-section 53. These ridges define a trough for collecting oil which escapes through the bearing 56, the trough leading the oil to the porous bearing 55 and any excess oil escaping from this bearing eventually works into the various bearings in the feed mechanism.

From the foregoing, it will be appreciated that one of the salient advantages of the present invention is the facility with which the machine can be completely assembled. For example, in assembling the bed-shaft in the machineframe, see Fig. 2, first the nipper release-rod 171, to gether with its sleeve 174, button 175 and spring 177, is properly placed in its bearings, following which the front section 53 of the bed-shaft is introduced through the opening 70 in the frame into its sleeve bearings 55 and 56. The driving link 3-5 is then inserted from beneath the bed 27 into the hollow 31 of the standard 21. The rear-shaftsection assembly, including the shaft 54, ball- bearings 67 and 68, sleeve 69 and the hand-wheel 71, is then inserted in the opening 70 with the crank-pin 65 passing through the lower end of the driving link 85 and entering the radial notch 63 formed in the end-face of the crank-cheek 62. Tightening of the set screws 72 locks the rear-shaftsection assembly in place and in so doing effectively secures the entire bed-shaft in its bearings.

The arm-shaft 33, which has the rock-arm 84 secured to it as by brazing or the like, is introduced through the access opening 36 into the ball bearing 83 (Fig. then through the needle-bar actuating rock-arm 80 and then into .thebaIl-bearing 582. The proper longitudinal position of the :arme'sha'ft is maintained by means of the nut 87, which nut is locked in its set position by the wedgescrew 88. As shown in Fig. 15, the rock-arm 84 has a cylindrical extremity which is adapted to slide into the apertured .upper .end of the driving link 85 as the armshaftapproaches its normal operating position, the driving link 85 bcingmaintained on the rock-arm 84 by the proximity of the rock-arm .to the machined surface 86 on the standard 21.

It will be appreciated also that the feeding mechanism (Figs. 3 and 10) comprises a unit assembly which is maintained in proper operating relation on the machinebed by means of a single stud 116 which is secured in :the bed 20 by set screws 117. The presser mechanism is constructed so that the components thereof canbe held in proper assembled relation by the set screw 95.

From the foregoing, it will be understood that the various mechanisms of the machine are preferably constructed so that they can be easily assembled in the machine-frame and secured in proper relative position by the use of relatively few set-screws. Obviously, this type of construction facilitates initial assembly and subsequent repair of the machine by average mechanics.

Havin thus set forth the nature of the invention, what 1 claim herein is:

1. A sewing machine having a frame including a bed and an overhanging bracket-arm, a rock-shaft journaled in said overhanging bracket-arm, a rock-arm mounted on said rock-shaft, an actuating shaft journaled in said bed and including axially aligned shaft-sections having their proximate ends releasably coupled together, said shaftsections being coupled together by a crank-pin secured to one of said shaft-sections and operatively associated with said other shaft-section, a transverse link having one end rotatably mounted on said crank, a rock-arm mounted on said rock-shaft for engagement with the other end of said lever, means operatively connecting said other end of said transverse link on said rock-arm, and a flat seat parallel with said link provided on said machine frame longitudinally spaced from the rock-arm and said link being positioned between said flat seat and the rockarm to retain said link operatively connected to said rock-arm.

2. A sewing machine having a frame provided with shaft-bearings and shaft-assembly openings through which shafts can be introduced endwise into their respective bearings and with a flat surface spaced from and facing said shaft assembly openings, a main-shaft endwise inserted through one of said shaft-assembly openings and provided with a cylindrical crank-pin, a bearing sleeve supporting said main-shaft and sized to enter and close one of said shaft-assembly openings, a second shaft endwise inserted into its bearings through another of said shaft-assembly openings, at lever-arm carried on said second shaft and having at its free end a cylindrical crankpin disposed so that its longitudinal axis projects toward and is normal to the fiat surface, and a link connected at one end to said crank-pin on said main-shaft and at its other end to the crank-pin on said second shaft, said link being positioned between said lever-arm and said flat surface, said link being connectable to each of said crankpins by the act of inserting the shafts into their respective bearings and the flat surface on said frame serving to constrain the link against lateral displacement off of the free ends of the crank-pins.

3. A sewing machine having a frame including a bed, a standard rising therefrom and merging into a bracketarm terminating in a head overhanging said bed, said frame provided with shaft-bearings and shaft-assembly openings through which shafts can be introduced endwise into their bearings, a partition located at the junction of said bracket-arm and standard and having a flat face formed thereon and facing said shaft-assembly openings, a main-shaft inserted through one of said shaft-assembly 11 12 openilngs and provided with a cylindrical crank-pin, a bear- 9 References Cited in the file of this patent ing s eeve supporting said main-shaft and sized to enter and close one of said shaft-assembly openings, a second UNITED STATES PATENTS, shaft inserted'into its bearings through another of said 1,191,232 Richards July 18, 1916 shaft-assembly openings and penetrating said partition, a 5 1,608,608 Ma ti N V- 30, 1926 lever-arm formed on said second shaft and provided with 1,765,927 Maier June 24, 1930 a cylindrical crank-pin projecting toward and having an 2,096,343 S ver Oct. 19, 1937 end-face operating in a plane parallel with the fiat face 2,282,047 Gr c cr May 5, 1942 on said partition, and a link connected at one end to said 2,394,510 Clayton Feb. 5 ,1946 crank-pin on said main-shaft and at its other end to the 10 2,411,459 Perkins et a1 Nov. 19, 1946 crank-pin on said second shaft, said link being positioned 2,414,168 Quist Ian. 14, 1947 between said lever-arm and said fiat surface and said 2,422,820 Best June 24,1947 link being connectable to each of said crank-pins by the 2,526,479 H hmann Oct. 17, 1950 act of inserting the shafts into their respective bearings 2,533,400 Saucr Dec. 12, 1950 and the flat wall on said partition serving to maintain 15 2,550, 53 Graesser et al- Apr. 24, 1951 the link in operative position upon both of said crankpins.

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